From c26f40268eb0a2bc9065fdcec68c6f63aecb0ed3 Mon Sep 17 00:00:00 2001
From: rbuckton <rbuckton@chronicles.org>
Date: Wed, 4 Jan 2017 20:38:10 -0800
Subject: [PATCH] Merge pull request #13277 from Microsoft/fix13276

---
 src/compiler/transformers/es2015.ts           | 37 +++++---
 ...sClassHeritageListMemberTypeAnnotations.js |  2 +-
 ...accessibleTypeInTypeParameterConstraint.js |  2 +-
 .../reference/abstractClassInLocalScope.js    |  2 +-
 .../abstractClassInLocalScopeIsAbstract.js    |  2 +-
 tests/baselines/reference/abstractProperty.js |  2 +-
 .../reference/abstractPropertyNegative.js     |  8 +-
 .../accessors_spec_section-4.5_inference.js   |  2 +-
 .../reference/aliasUsageInAccessorsOfClass.js |  2 +-
 .../baselines/reference/aliasUsageInArray.js  |  2 +-
 .../aliasUsageInFunctionExpression.js         |  2 +-
 .../reference/aliasUsageInGenericFunction.js  |  2 +-
 .../reference/aliasUsageInIndexerOfClass.js   |  2 +-
 .../reference/aliasUsageInObjectLiteral.js    |  2 +-
 .../reference/aliasUsageInOrExpression.js     |  2 +-
 ...aliasUsageInTypeArgumentOfExtendsClause.js |  4 +-
 .../reference/aliasUsageInVarAssignment.js    |  2 +-
 .../reference/ambiguousOverloadResolution.js  |  2 +-
 .../reference/apparentTypeSubtyping.js        |  4 +-
 .../reference/apparentTypeSupertype.js        |  2 +-
 .../reference/arrayAssignmentTest1.js         |  2 +-
 .../reference/arrayAssignmentTest2.js         |  2 +-
 .../reference/arrayBestCommonTypes.js         |  4 +-
 .../reference/arrayLiteralTypeInference.js    |  4 +-
 tests/baselines/reference/arrayLiterals.js    |  4 +-
 .../arrayLiteralsWithRecursiveGenerics.js     |  2 +-
 ...rayOfSubtypeIsAssignableToReadonlyArray.js |  4 +-
 .../assignmentCompatWithCallSignatures3.js    |  6 +-
 .../assignmentCompatWithCallSignatures4.js    |  6 +-
 .../assignmentCompatWithCallSignatures5.js    |  6 +-
 .../assignmentCompatWithCallSignatures6.js    |  6 +-
 ...ssignmentCompatWithConstructSignatures3.js |  6 +-
 ...ssignmentCompatWithConstructSignatures4.js |  6 +-
 ...ssignmentCompatWithConstructSignatures5.js |  6 +-
 ...ssignmentCompatWithConstructSignatures6.js |  6 +-
 .../assignmentCompatWithNumericIndexer.js     |  2 +-
 .../assignmentCompatWithNumericIndexer3.js    |  2 +-
 .../assignmentCompatWithObjectMembers4.js     |  8 +-
 ...nmentCompatWithObjectMembersOptionality.js |  4 +-
 ...mentCompatWithObjectMembersOptionality2.js |  4 +-
 .../assignmentCompatWithStringIndexer.js      |  4 +-
 .../reference/asyncImportedPromise_es5.js     |  2 +-
 .../reference/asyncMethodWithSuper_es5.js     |  2 +-
 .../reference/asyncQualifiedReturnType_es5.js |  2 +-
 .../reference/awaitClassExpression_es5.js     |  2 +-
 .../reference/baseIndexSignatureResolution.js |  2 +-
 .../reference/baseTypeOrderChecking.js        |  4 +-
 .../baseTypeWrappingInstantiationChain.js     |  4 +-
 tests/baselines/reference/bases.js            |  2 +-
 .../bestCommonTypeOfConditionalExpressions.js |  4 +-
 ...bestCommonTypeOfConditionalExpressions2.js |  4 +-
 .../reference/bestCommonTypeOfTuple2.js       |  4 +-
 ...allSignatureAssignabilityInInheritance2.js |  6 +-
 ...allSignatureAssignabilityInInheritance3.js |  6 +-
 ...allSignatureAssignabilityInInheritance4.js |  6 +-
 ...allSignatureAssignabilityInInheritance5.js |  6 +-
 ...allSignatureAssignabilityInInheritance6.js |  6 +-
 tests/baselines/reference/castingTuple.js     |  4 +-
 .../baselines/reference/chainedAssignment3.js |  2 +-
 ...arameterConstrainedToOtherTypeParameter.js |  4 +-
 .../checkSuperCallBeforeThisAccessing2.js     |  2 +-
 .../checkSuperCallBeforeThisAccessing3.js     |  2 +-
 .../checkSuperCallBeforeThisAccessing4.js     |  2 +-
 .../checkSuperCallBeforeThisAccessing6.js     |  2 +-
 .../checkSuperCallBeforeThisAccessing8.js     |  2 +-
 .../reference/circularImportAlias.js          |  2 +-
 .../circularTypeofWithFunctionModule.js       |  2 +-
 .../classAbstractConstructorAssignability.js  |  4 +-
 .../reference/classAbstractCrashedOnce.js     |  2 +-
 .../reference/classAbstractExtends.js         |  8 +-
 .../reference/classAbstractFactoryFunction.js |  2 +-
 .../reference/classAbstractGeneric.js         | 12 +--
 .../reference/classAbstractInAModule.js       |  2 +-
 .../reference/classAbstractInheritance.js     | 16 ++--
 .../reference/classAbstractInstantiations1.js |  4 +-
 .../reference/classAbstractInstantiations2.js |  8 +-
 .../classAbstractOverrideWithAbstract.js      |  8 +-
 .../reference/classAbstractSuperCalls.js      |  6 +-
 .../classAbstractUsingAbstractMethod1.js      |  4 +-
 .../classAbstractUsingAbstractMethods2.js     | 14 +--
 .../classConstructorAccessibility4.js         |  4 +-
 .../classConstructorAccessibility5.js         |  2 +-
 ...clarationMergedInModuleWithContinuation.js |  2 +-
 .../classDeclaredBeforeClassFactory.js        |  2 +-
 .../classDoesNotDependOnBaseTypes.js          |  2 +-
 tests/baselines/reference/classExpression2.js |  2 +-
 tests/baselines/reference/classExpression3.js |  4 +-
 .../classExpressionExtendingAbstractClass.js  |  2 +-
 .../reference/classExtendingBuiltinType.js    | 20 ++--
 .../reference/classExtendingClass.js          |  4 +-
 .../reference/classExtendingClassLikeType.js  |  6 +-
 .../reference/classExtendingNonConstructor.js | 14 +--
 .../baselines/reference/classExtendingNull.js |  2 -
 .../reference/classExtendingPrimitive.js      | 17 ++--
 .../reference/classExtendingPrimitive2.js     |  1 -
 .../reference/classExtendingQualifiedName.js  |  2 +-
 .../reference/classExtendingQualifiedName2.js |  2 +-
 .../reference/classExtendsAcrossFiles.js      |  4 +-
 ...sMergedWithModuleNotReferingConstructor.js |  2 +-
 ...tendsClauseClassNotReferringConstructor.js |  2 +-
 .../reference/classExtendsEveryObjectType.js  | 12 +--
 .../reference/classExtendsEveryObjectType2.js |  4 +-
 .../reference/classExtendsInterface.js        |  4 +-
 .../classExtendsInterfaceInExpression.js      |  2 +-
 .../classExtendsInterfaceInModule.js          |  6 +-
 .../baselines/reference/classExtendsItself.js |  6 +-
 .../reference/classExtendsItselfIndirectly.js | 12 +--
 .../classExtendsItselfIndirectly2.js          | 12 +--
 .../classExtendsItselfIndirectly3.js          | 12 +--
 .../classExtendsMultipleBaseClasses.js        |  2 +-
 tests/baselines/reference/classExtendsNull.js |  3 +-
 ...classExtendsShadowedConstructorFunction.js |  2 +-
 .../classExtendsValidConstructorFunction.js   |  2 +-
 .../classHeritageWithTrailingSeparator.js     |  2 +-
 .../reference/classImplementsClass2.js        |  2 +-
 .../reference/classImplementsClass3.js        |  2 +-
 .../reference/classImplementsClass4.js        |  2 +-
 .../reference/classImplementsClass5.js        |  2 +-
 .../reference/classImplementsClass6.js        |  2 +-
 tests/baselines/reference/classIndexer3.js    |  2 +-
 tests/baselines/reference/classInheritence.js |  4 +-
 .../reference/classIsSubtypeOfBaseType.js     |  4 +-
 tests/baselines/reference/classOrder2.js      |  2 +-
 tests/baselines/reference/classOrderBug.js    |  2 +-
 .../reference/classSideInheritance1.js        |  2 +-
 tests/baselines/reference/classUpdateTests.js |  8 +-
 .../classWithBaseClassButNoConstructor.js     |  8 +-
 .../reference/classWithConstructors.js        |  4 +-
 .../reference/classWithProtectedProperty.js   |  2 +-
 .../reference/classWithStaticMembers.js       |  2 +-
 tests/baselines/reference/classdecl.js        |  6 +-
 .../reference/clodulesDerivedClasses.js       |  2 +-
 ...llisionSuperAndLocalFunctionInAccessors.js |  4 +-
 .../collisionSuperAndLocalFunctionInMethod.js |  4 +-
 ...ollisionSuperAndLocalFunctionInProperty.js |  2 +-
 .../collisionSuperAndLocalVarInAccessors.js   |  4 +-
 .../collisionSuperAndLocalVarInMethod.js      |  4 +-
 .../collisionSuperAndLocalVarInProperty.js    |  2 +-
 .../collisionSuperAndNameResolution.js        |  2 +-
 .../reference/collisionSuperAndParameter1.js  |  2 +-
 ...xpressionAndLocalVarWithSuperExperssion.js |  4 +-
 .../reference/commentsInheritance.js          |  2 +-
 .../comparisonOperatorWithIdenticalObjects.js |  4 +-
 ...ithNoRelationshipObjectsOnCallSignature.js |  2 +-
 ...lationshipObjectsOnConstructorSignature.js |  2 +-
 ...thNoRelationshipObjectsOnIndexSignature.js |  2 +-
 ...nshipObjectsOnInstantiatedCallSignature.js |  2 +-
 ...jectsOnInstantiatedConstructorSignature.js |  2 +-
 ...peratorWithSubtypeObjectOnCallSignature.js |  2 +-
 ...WithSubtypeObjectOnConstructorSignature.js |  2 +-
 ...eratorWithSubtypeObjectOnIndexSignature.js |  2 +-
 ...ubtypeObjectOnInstantiatedCallSignature.js |  2 +-
 ...bjectOnInstantiatedConstructorSignature.js |  2 +-
 ...isonOperatorWithSubtypeObjectOnProperty.js |  4 +-
 .../reference/complexClassRelationships.js    |  2 +-
 ...catedGenericRecursiveBaseClassReference.js |  2 +-
 .../reference/computedPropertyNames24_ES5.js  |  2 +-
 .../reference/computedPropertyNames25_ES5.js  |  2 +-
 .../reference/computedPropertyNames26_ES5.js  |  2 +-
 .../reference/computedPropertyNames27_ES5.js  |  2 +-
 .../reference/computedPropertyNames31_ES5.js  |  2 +-
 .../reference/computedPropertyNames43_ES5.js  |  2 +-
 .../reference/computedPropertyNames44_ES5.js  |  2 +-
 .../reference/computedPropertyNames45_ES5.js  |  2 +-
 .../conditionalOperatorWithIdenticalBCT.js    |  4 +-
 .../conditionalOperatorWithoutIdenticalBCT.js |  4 +-
 .../reference/constantOverloadFunction.js     |  6 +-
 .../constantOverloadFunctionNoSubtypeError.js |  6 +-
 ...nstraintCheckInGenericBaseTypeReference.js |  2 +-
 ...uctSignatureAssignabilityInInheritance2.js |  6 +-
 ...uctSignatureAssignabilityInInheritance3.js |  6 +-
 ...uctSignatureAssignabilityInInheritance4.js |  6 +-
 ...uctSignatureAssignabilityInInheritance5.js |  6 +-
 ...uctSignatureAssignabilityInInheritance6.js |  6 +-
 ...uctorFunctionTypeIsAssignableToBaseType.js |  4 +-
 .../constructorHasPrototypeProperty.js        |  4 +-
 .../reference/constructorOverloads3.js        |  2 +-
 ...constructorWithIncompleteTypeAnnotation.js |  2 +-
 .../contextualTypingArrayOfLambdas.js         |  4 +-
 ...contextualTypingOfConditionalExpression.js |  4 +-
 ...ontextualTypingOfConditionalExpression2.js |  4 +-
 ...urcePropertyIsRelatableToTargetProperty.js |  2 +-
 .../reference/declFileClassExtendsNull.js     |  1 -
 .../declFileForFunctionTypeAsTypeParameter.js |  2 +-
 ...ileGenericClassWithGenericExtendedClass.js |  2 +-
 .../reference/declFileGenericType.js          |  2 +-
 ...lictingWithClassReferredByExtendsClause.js |  4 +-
 ...dsClauseThatHasItsContainerNameConflict.js |  2 +-
 .../declarationEmitExpressionInExtends.js     |  2 +-
 .../declarationEmitExpressionInExtends2.js    |  2 +-
 .../declarationEmitExpressionInExtends3.js    |  8 +-
 .../declarationEmitExpressionInExtends4.js    |  6 +-
 .../declarationEmitNameConflicts3.js          |  2 +-
 .../declarationEmitProtectedMembers.js        |  4 +-
 .../declarationEmitThisPredicates01.js        |  2 +-
 ...tionEmitThisPredicatesWithPrivateName01.js |  2 +-
 .../reference/declareDottedExtend.js          |  4 +-
 .../reference/decoratorOnClassConstructor4.js |  2 +-
 .../reference/decoratorOnClassMethod12.js     |  2 +-
 ...derivedClassConstructorWithoutSuperCall.js |  8 +-
 ...ClassFunctionOverridesBaseClassAccessor.js |  2 +-
 .../derivedClassIncludesInheritedMembers.js   |  4 +-
 ...idesIndexersWithAssignmentCompatibility.js |  4 +-
 .../derivedClassOverridesPrivates.js          |  4 +-
 .../derivedClassOverridesProtectedMembers2.js |  2 +-
 .../derivedClassOverridesProtectedMembers4.js |  4 +-
 .../derivedClassOverridesPublicMembers.js     |  2 +-
 .../derivedClassOverridesWithoutSubtype.js    |  4 +-
 .../derivedClassParameterProperties.js        | 12 +--
 ...dClassSuperCallsInNonConstructorMembers.js |  2 +-
 .../reference/derivedClassTransitivity.js     |  4 +-
 .../reference/derivedClassTransitivity2.js    |  4 +-
 .../reference/derivedClassTransitivity3.js    |  4 +-
 .../reference/derivedClassTransitivity4.js    |  4 +-
 .../reference/derivedClassWithAny.js          |  4 +-
 ...ivateInstanceShadowingProtectedInstance.js |  2 +-
 ...hPrivateInstanceShadowingPublicInstance.js |  2 +-
 ...thPrivateStaticShadowingProtectedStatic.js |  2 +-
 ...sWithPrivateStaticShadowingPublicStatic.js |  2 +-
 .../derivedClassWithoutExplicitConstructor.js |  4 +-
 ...derivedClassWithoutExplicitConstructor2.js |  4 +-
 ...derivedClassWithoutExplicitConstructor3.js |  4 +-
 tests/baselines/reference/derivedClasses.js   |  4 +-
 .../reference/derivedGenericClassWithAny.js   |  4 +-
 ...sesHiddenBaseCallViaSuperPropertyAccess.js |  2 +-
 .../derivedTypeDoesNotRequireExtendsClause.js |  2 +-
 .../reference/emitThisInSuperMethodCall.js    |  2 +-
 tests/baselines/reference/emptyModuleName.js  |  2 +-
 ...rorForwardReferenceForwadingConstructor.js |  2 +-
 tests/baselines/reference/errorSuperCalls.js  |  4 +-
 .../reference/errorSuperPropertyAccess.js     |  2 +-
 .../reference/errorsInGenericTypeReference.js |  2 +-
 .../reference/es6ClassSuperCodegenBug.js      |  2 +-
 tests/baselines/reference/es6ClassTest2.js    |  2 +-
 tests/baselines/reference/es6ClassTest7.js    |  2 +-
 .../exportAssignmentOfGenericType1.js         |  2 +-
 .../exportDeclarationInInternalModule.js      |  2 +-
 tests/baselines/reference/extBaseClass1.js    |  6 +-
 tests/baselines/reference/extBaseClass2.js    |  4 +-
 .../extendAndImplementTheSameBaseType.js      |  2 +-
 .../extendAndImplementTheSameBaseType2.js     |  2 +-
 .../extendBaseClassBeforeItsDeclared.js       |  2 +-
 .../extendClassExpressionFromModule.js        |  2 +-
 .../extendConstructSignatureInInterface.js    |  2 +-
 .../reference/extendNonClassSymbol1.js        |  2 +-
 .../reference/extendNonClassSymbol2.js        |  2 +-
 .../extendPrivateConstructorClass.js          |  2 +-
 ...xtendingClassFromAliasAndUsageInIndexer.js |  4 +-
 .../reference/extendsClauseAlreadySeen.js     |  2 +-
 .../reference/extendsClauseAlreadySeen2.js    |  2 +-
 tests/baselines/reference/fluentClasses.js    |  4 +-
 tests/baselines/reference/for-inStatements.js |  2 +-
 .../reference/for-inStatementsInvalid.js      |  2 +-
 .../forStatementsMultipleInvalidDecl.js       |  2 +-
 .../reference/functionImplementationErrors.js |  4 +-
 .../reference/functionImplementations.js      |  4 +-
 .../reference/functionSubtypingOfVarArgs.js   |  2 +-
 .../reference/functionSubtypingOfVarArgs2.js  |  2 +-
 .../reference/generatedContextualTyping.js    |  4 +-
 .../genericBaseClassLiteralProperty.js        |  2 +-
 .../genericBaseClassLiteralProperty2.js       |  2 +-
 ...allWithConstraintsTypeArgumentInference.js |  4 +-
 .../genericCallWithObjectTypeArgs2.js         |  4 +-
 ...icCallWithObjectTypeArgsAndConstraints2.js |  2 +-
 ...icCallWithObjectTypeArgsAndConstraints3.js |  4 +-
 .../genericCallbacksAndClassHierarchy.js      |  2 +-
 .../genericClassExpressionInFunction.js       | 12 +--
 ...sInheritsConstructorFromNonGenericClass.js |  4 +-
 .../reference/genericClassStaticMethod.js     |  2 +-
 tests/baselines/reference/genericClasses3.js  |  2 +-
 .../genericDerivedTypeWithSpecializedBase.js  |  2 +-
 .../genericDerivedTypeWithSpecializedBase2.js |  2 +-
 .../genericInheritedDefaultConstructors.js    |  2 +-
 .../reference/genericPrototypeProperty2.js    |  4 +-
 .../reference/genericPrototypeProperty3.js    |  4 +-
 ...ericRecursiveImplicitConstructorErrors2.js |  2 +-
 ...ericRecursiveImplicitConstructorErrors3.js |  2 +-
 .../reference/genericTypeAssertions2.js       |  2 +-
 .../reference/genericTypeAssertions4.js       |  4 +-
 .../reference/genericTypeAssertions6.js       |  2 +-
 ...genericTypeReferenceWithoutTypeArgument.js |  4 +-
 ...enericTypeReferenceWithoutTypeArgument2.js |  4 +-
 .../genericWithIndexerOfTypeParameterType2.js |  4 +-
 .../reference/heterogeneousArrayLiterals.js   |  4 +-
 .../reference/ifDoWhileStatements.js          |  2 +-
 .../illegalSuperCallsInConstructor.js         |  2 +-
 .../implementClausePrecedingExtends.js        |  2 +-
 ...gAnInterfaceExtendingClassWithPrivates2.js | 22 ++---
 ...AnInterfaceExtendingClassWithProtecteds.js |  8 +-
 .../baselines/reference/importAsBaseClass.js  |  2 +-
 tests/baselines/reference/importHelpers.js    |  4 +-
 tests/baselines/reference/importHelpersAmd.js |  2 +-
 .../importHelpersInIsolatedModules.js         |  4 +-
 .../reference/importHelpersNoHelpers.js       |  4 +-
 .../reference/importHelpersNoModule.js        |  4 +-
 .../reference/importHelpersOutFile.js         |  4 +-
 .../reference/importHelpersSystem.js          |  2 +-
 .../reference/importShadowsGlobalName.js      |  2 +-
 .../reference/importUsedInExtendsList1.js     |  2 +-
 .../reference/indexerConstraints2.js          |  8 +-
 .../reference/indirectSelfReference.js        |  4 +-
 .../reference/indirectSelfReferenceGeneric.js |  4 +-
 .../infinitelyExpandingTypesNonGenericBase.js |  2 +-
 .../inheritFromGenericTypeParameter.js        |  2 +-
 ...SameNamePrivatePropertiesFromSameOrigin.js |  4 +-
 tests/baselines/reference/inheritance.js      |  8 +-
 tests/baselines/reference/inheritance1.js     |  8 +-
 ...itanceGrandParentPrivateMemberCollision.js |  4 +-
 ...tPrivateMemberCollisionWithPublicMember.js |  4 +-
 ...tPublicMemberCollisionWithPrivateMember.js |  4 +-
 ...ritanceMemberAccessorOverridingAccessor.js |  2 +-
 ...heritanceMemberAccessorOverridingMethod.js |  2 +-
 ...ritanceMemberAccessorOverridingProperty.js |  2 +-
 ...inheritanceMemberFuncOverridingAccessor.js |  2 +-
 .../inheritanceMemberFuncOverridingMethod.js  |  2 +-
 ...inheritanceMemberFuncOverridingProperty.js |  2 +-
 ...ritanceMemberPropertyOverridingAccessor.js |  2 +-
 ...heritanceMemberPropertyOverridingMethod.js |  2 +-
 ...ritanceMemberPropertyOverridingProperty.js |  2 +-
 .../inheritanceOfGenericConstructorMethod1.js |  2 +-
 .../inheritanceOfGenericConstructorMethod2.js |  4 +-
 ...ritanceStaticAccessorOverridingAccessor.js |  2 +-
 ...heritanceStaticAccessorOverridingMethod.js |  2 +-
 ...ritanceStaticAccessorOverridingProperty.js |  2 +-
 ...inheritanceStaticFuncOverridingAccessor.js |  2 +-
 ...eStaticFuncOverridingAccessorOfFuncType.js |  2 +-
 .../inheritanceStaticFuncOverridingMethod.js  |  2 +-
 ...inheritanceStaticFuncOverridingProperty.js |  2 +-
 ...eStaticFuncOverridingPropertyOfFuncType.js |  2 +-
 ...taticFunctionOverridingInstanceProperty.js |  2 +-
 .../inheritanceStaticMembersCompatible.js     |  2 +-
 .../inheritanceStaticMembersIncompatible.js   |  2 +-
 ...ritanceStaticPropertyOverridingAccessor.js |  2 +-
 ...heritanceStaticPropertyOverridingMethod.js |  2 +-
 ...ritanceStaticPropertyOverridingProperty.js |  2 +-
 .../inheritedConstructorWithRestParams.js     |  2 +-
 .../inheritedConstructorWithRestParams2.js    |  4 +-
 .../inheritedModuleMembersForClodule.js       |  4 +-
 .../reference/instanceOfAssignability.js      |  4 +-
 ...nstancePropertiesInheritedIntoClassType.js |  4 +-
 .../reference/instanceSubtypeCheck2.js        |  2 +-
 ...nstanceofWithStructurallyIdenticalTypes.js |  4 +-
 .../instantiatedReturnTypeContravariance.js   |  2 +-
 .../reference/interfaceClassMerging.js        |  2 +-
 .../reference/interfaceClassMerging2.js       |  2 +-
 .../reference/interfaceExtendsClass1.js       |  6 +-
 .../interfaceExtendsClassWithPrivate1.js      |  2 +-
 .../interfaceExtendsClassWithPrivate2.js      |  4 +-
 .../reference/interfaceImplementation8.js     |  8 +-
 .../invalidModuleWithStatementsOfEveryKind.js | 12 +--
 .../invalidMultipleVariableDeclarations.js    |  2 +-
 .../reference/invalidReturnStatements.js      |  2 +-
 .../isolatedModulesImportExportElision.js     |  2 +-
 .../baselines/reference/jsxInExtendsClause.js |  4 +-
 tests/baselines/reference/jsxViaImport.2.js   |  2 +-
 tests/baselines/reference/jsxViaImport.js     |  2 +-
 .../reference/keyofAndIndexedAccess.js        |  2 +-
 tests/baselines/reference/lambdaArgCrash.js   |  2 +-
 tests/baselines/reference/localTypes1.js      |  4 +-
 tests/baselines/reference/m7Bugs.js           |  2 +-
 .../reference/mergedDeclarations5.js          |  2 +-
 .../reference/mergedDeclarations6.js          |  2 +-
 .../mergedInheritedClassInterface.js          |  4 +-
 .../mergedInterfacesWithInheritedPrivates2.js |  4 +-
 .../mergedInterfacesWithInheritedPrivates3.js |  2 +-
 tests/baselines/reference/moduleAsBaseType.js |  2 +-
 .../moduleImportedForTypeArgumentPosition.js  |  2 +-
 .../moduleWithStatementsOfEveryKind.js        |  8 +-
 .../reference/multipleInheritance.js          | 12 +--
 .../mutuallyRecursiveGenericBaseTypes2.js     |  2 +-
 tests/baselines/reference/noEmitHelpers.js    |  2 +-
 .../noImplicitAnyMissingGetAccessor.js        |  2 +-
 .../noImplicitAnyMissingSetAccessor.js        |  2 +-
 ...enericClassExtendingGenericClassWithAny.js |  2 +-
 ...cIndexerConstrainsPropertyDeclarations2.js |  2 +-
 .../reference/numericIndexerConstraint3.js    |  2 +-
 .../reference/numericIndexerConstraint4.js    |  2 +-
 .../reference/numericIndexerTyping2.js        |  2 +-
 ...objectTypeHidingMembersOfExtendedObject.js |  2 +-
 ...objectTypesIdentityWithNumericIndexers1.js |  4 +-
 ...objectTypesIdentityWithNumericIndexers2.js |  6 +-
 ...objectTypesIdentityWithNumericIndexers3.js |  4 +-
 .../objectTypesIdentityWithPrivates.js        |  4 +-
 .../objectTypesIdentityWithPrivates2.js       |  2 +-
 .../objectTypesIdentityWithPrivates3.js       |  4 +-
 .../objectTypesIdentityWithStringIndexers.js  |  4 +-
 .../objectTypesIdentityWithStringIndexers2.js |  6 +-
 .../optionalConstructorArgInSuper.js          |  2 +-
 tests/baselines/reference/optionalMethods.js  |  2 +-
 .../reference/optionalParamInOverride.js      |  2 +-
 .../baselines/reference/outModuleConcatAmd.js |  2 +-
 .../outModuleConcatAmd.sourcemap.txt          |  4 +-
 .../reference/outModuleConcatSystem.js        |  2 +-
 .../outModuleConcatSystem.sourcemap.txt       |  4 +-
 .../reference/outModuleTripleSlashRefs.js     |  2 +-
 .../outModuleTripleSlashRefs.sourcemap.txt    |  4 +-
 tests/baselines/reference/overload1.js        |  4 +-
 .../overloadOnConstConstraintChecks1.js       |  6 +-
 .../overloadOnConstConstraintChecks2.js       |  4 +-
 .../overloadOnConstConstraintChecks3.js       |  4 +-
 .../overloadOnConstConstraintChecks4.js       |  6 +-
 .../overloadOnConstantsInvalidOverload1.js    |  6 +-
 .../baselines/reference/overloadResolution.js |  6 +-
 .../overloadResolutionClassConstructors.js    |  6 +-
 .../overloadResolutionConstructors.js         |  6 +-
 .../reference/overloadingOnConstants1.js      |  6 +-
 .../reference/overloadingOnConstants2.js      |  2 +-
 .../overridingPrivateStaticMembers.js         |  2 +-
 .../reference/parseErrorInHeritageClause1.js  |  2 +-
 tests/baselines/reference/parser509630.js     |  2 +-
 tests/baselines/reference/parserAstSpans1.js  |  2 +-
 .../reference/parserClassDeclaration1.js      |  2 +-
 .../reference/parserClassDeclaration3.js      |  2 +-
 .../reference/parserClassDeclaration4.js      |  2 +-
 .../reference/parserClassDeclaration5.js      |  2 +-
 .../reference/parserClassDeclaration6.js      |  2 +-
 ...rrorRecovery_ExtendsOrImplementsClause2.js |  2 +-
 ...rrorRecovery_ExtendsOrImplementsClause4.js |  2 +-
 ...rrorRecovery_ExtendsOrImplementsClause5.js |  2 +-
 .../parserGenericsInTypeContexts1.js          |  2 +-
 .../parserGenericsInTypeContexts2.js          |  2 +-
 ...artiallyAnnotatedFunctionInferenceError.js |  2 +-
 ...tatedFunctionInferenceWithTypeParameter.js |  2 +-
 tests/baselines/reference/primitiveMembers.js |  2 +-
 tests/baselines/reference/privacyClass.js     | 48 +++++-----
 .../privacyClassExtendsClauseDeclFile.js      | 46 ++++-----
 tests/baselines/reference/privacyGloClass.js  | 20 ++--
 .../reference/privateAccessInSubclass1.js     |  2 +-
 .../privateInstanceMemberAccessibility.js     |  2 +-
 ...tedMembersAreNotAccessibleDestructuring.js |  2 +-
 .../privateStaticMemberAccessibility.js       |  2 +-
 .../privateStaticNotAccessibleInClodule2.js   |  2 +-
 .../amd/testGlo.js                            |  8 +-
 .../node/testGlo.js                           |  8 +-
 .../reference/project/prologueEmit/amd/out.js |  2 +-
 .../project/prologueEmit/node/out.js          |  2 +-
 .../amd/m'ain.js                              |  2 +-
 .../node/m'ain.js                             |  2 +-
 .../reference/propertiesAndIndexers.js        |  2 +-
 tests/baselines/reference/propertyAccess.js   |  2 +-
 ...tyAccessOnTypeParameterWithConstraints2.js |  2 +-
 ...tyAccessOnTypeParameterWithConstraints3.js |  2 +-
 ...tyAccessOnTypeParameterWithConstraints5.js |  2 +-
 ...sPropertyAccessibleWithinNestedSubclass.js |  4 +-
 ...PropertyAccessibleWithinNestedSubclass1.js |  8 +-
 ...edClassPropertyAccessibleWithinSubclass.js |  2 +-
 ...dClassPropertyAccessibleWithinSubclass2.js |  8 +-
 ...dClassPropertyAccessibleWithinSubclass3.js |  2 +-
 .../protectedInstanceMemberAccessibility.js   |  4 +-
 tests/baselines/reference/protectedMembers.js | 14 +--
 ...icClassPropertyAccessibleWithinSubclass.js |  6 +-
 ...cClassPropertyAccessibleWithinSubclass2.js |  4 +-
 ...solution-does-not-affect-class-heritage.js |  2 +-
 .../reference/recursiveBaseCheck3.js          |  4 +-
 .../reference/recursiveBaseCheck4.js          |  2 +-
 .../reference/recursiveBaseCheck6.js          |  2 +-
 .../recursiveBaseConstructorCreation1.js      |  2 +-
 ...ssInstantiationsWithDefaultConstructors.js |  2 +-
 .../reference/recursiveClassReferenceTest.js  |  2 +-
 .../recursiveClassReferenceTest.sourcemap.txt |  4 +-
 .../reference/recursiveComplicatedClasses.js  |  6 +-
 ...sivelySpecializedConstructorDeclaration.js |  2 +-
 .../reference/reexportClassDefinition.js      |  2 +-
 ...lassDeclarationWhenInBaseTypeResolution.js | 94 +++++++++----------
 tests/baselines/reference/returnStatements.js |  2 +-
 ...peCheckExtendedClassInsidePublicMethod2.js |  2 +-
 ...peCheckExtendedClassInsideStaticMethod1.js |  2 +-
 .../reference/shadowPrivateMembers.js         |  2 +-
 ...sWithDefaultConstructorAndExtendsClause.js |  2 +-
 ...hDefaultConstructorAndExtendsClause.js.map |  2 +-
 ...tConstructorAndExtendsClause.sourcemap.txt |  8 +-
 .../specializedInheritedConstructors1.js      |  2 +-
 .../specializedOverloadWithRestParameters.js  |  2 +-
 tests/baselines/reference/staticFactory1.js   |  2 +-
 .../baselines/reference/staticInheritance.js  |  2 +-
 .../staticMemberAccessOffDerivedType1.js      |  2 +-
 tests/baselines/reference/staticPropSuper.js  |  8 +-
 .../reference/strictModeInConstructor.js      |  4 +-
 .../reference/strictModeReservedWord.js       |  2 +-
 ...trictModeReservedWordInClassDeclaration.js |  4 +-
 ...gIndexerConstrainsPropertyDeclarations2.js |  2 +-
 ...ubSubClassCanAccessProtectedConstructor.js |  4 +-
 .../reference/subtypesOfTypeParameter.js      |  2 +-
 .../subtypesOfTypeParameterWithConstraints.js | 58 ++++++------
 ...subtypesOfTypeParameterWithConstraints4.js | 18 ++--
 ...OfTypeParameterWithRecursiveConstraints.js | 36 +++----
 .../reference/subtypingTransitivity.js        |  4 +-
 .../reference/subtypingWithCallSignatures2.js |  6 +-
 .../reference/subtypingWithCallSignatures3.js |  6 +-
 .../reference/subtypingWithCallSignatures4.js |  6 +-
 .../subtypingWithConstructSignatures2.js      |  6 +-
 .../subtypingWithConstructSignatures3.js      |  6 +-
 .../subtypingWithConstructSignatures4.js      |  6 +-
 .../subtypingWithConstructSignatures5.js      |  6 +-
 .../subtypingWithConstructSignatures6.js      |  6 +-
 .../reference/subtypingWithNumericIndexer.js  | 12 +--
 .../reference/subtypingWithNumericIndexer3.js | 14 +--
 .../reference/subtypingWithNumericIndexer4.js |  6 +-
 .../reference/subtypingWithObjectMembers.js   | 16 ++--
 .../reference/subtypingWithObjectMembers4.js  |  8 +-
 ...subtypingWithObjectMembersAccessibility.js |  8 +-
 ...ubtypingWithObjectMembersAccessibility2.js | 14 +--
 .../reference/subtypingWithStringIndexer.js   | 12 +--
 .../reference/subtypingWithStringIndexer3.js  | 14 +--
 .../reference/subtypingWithStringIndexer4.js  |  6 +-
 tests/baselines/reference/super.js            |  4 +-
 tests/baselines/reference/super1.js           | 10 +-
 tests/baselines/reference/super2.js           |  8 +-
 tests/baselines/reference/superAccess.js      |  2 +-
 .../reference/superAccessInFatArrow1.js       |  2 +-
 .../reference/superCallAssignResult.js        |  2 +-
 .../superCallBeforeThisAccessing3.js          |  2 +-
 .../superCallBeforeThisAccessing4.js          |  9 +-
 .../superCallBeforeThisAccessing5.js          |  4 +-
 .../superCallBeforeThisAccessing7.js          |  2 +-
 .../superCallBeforeThisAccessing8.js          |  2 +-
 .../reference/superCallInStaticMethod.js      |  2 +-
 .../superCallInsideClassDeclaration.js        |  2 +-
 .../superCallInsideClassExpression.js         |  2 +-
 .../superCallInsideObjectLiteralExpression.js |  2 +-
 .../superCallWithMissingBaseClass.js          |  2 +-
 tests/baselines/reference/superCalls.js       |  2 +-
 .../reference/superCallsInConstructor.js      |  2 +-
 .../baselines/reference/superInCatchBlock1.js |  2 +-
 .../reference/superInConstructorParam1.js     |  2 +-
 .../reference/superInObjectLiterals_ES5.js    |  2 +-
 tests/baselines/reference/superNewCall1.js    |  2 +-
 .../reference/superPropertyAccess.js          |  2 +-
 ...essInComputedPropertiesOfNestedType_ES5.js |  2 +-
 .../reference/superPropertyAccess_ES5.js      |  2 +-
 ...perPropertyInConstructorBeforeSuperCall.js |  2 +-
 .../reference/superSymbolIndexedAccess5.js    |  2 +-
 .../reference/superSymbolIndexedAccess6.js    |  2 +-
 .../reference/superWithTypeArgument.js        |  2 +-
 .../reference/superWithTypeArgument2.js       |  2 +-
 .../reference/superWithTypeArgument3.js       |  2 +-
 ...side-object-literal-getters-and-setters.js |  2 +-
 tests/baselines/reference/switchStatements.js |  2 +-
 .../reference/systemModuleWithSuperClass.js   |  2 +-
 .../reference/thisInInvalidContexts.js        |  2 +-
 .../thisInInvalidContextsExternalModule.js    |  2 +-
 .../reference/thisTypeInFunctions.js          |  6 +-
 .../reference/thisTypeInFunctionsNegative.js  |  4 +-
 .../tsxCorrectlyParseLessThanComparison1.js   |  2 +-
 .../baselines/reference/tsxDynamicTagName5.js |  2 +-
 .../baselines/reference/tsxDynamicTagName7.js |  2 +-
 .../baselines/reference/tsxDynamicTagName8.js |  2 +-
 .../baselines/reference/tsxDynamicTagName9.js |  2 +-
 .../reference/tsxExternalModuleEmit1.js       |  4 +-
 .../tsxStatelessFunctionComponents2.js        |  2 +-
 .../reference/tsxUnionTypeComponent1.js       |  4 +-
 tests/baselines/reference/typeAssertions.js   |  2 +-
 .../baselines/reference/typeGuardFunction.js  |  2 +-
 .../reference/typeGuardFunctionErrors.js      |  2 +-
 .../reference/typeGuardFunctionGenerics.js    |  2 +-
 .../reference/typeGuardFunctionOfFormThis.js  | 12 +--
 .../typeGuardFunctionOfFormThisErrors.js      |  4 +-
 .../reference/typeGuardOfFormInstanceOf.js    |  2 +-
 .../reference/typeGuardOfFormIsType.js        |  2 +-
 .../reference/typeGuardOfFormThisMember.js    |  2 +-
 .../typeGuardOfFormThisMemberErrors.js        |  2 +-
 tests/baselines/reference/typeMatch2.js       |  2 +-
 tests/baselines/reference/typeOfSuperCall.js  |  2 +-
 .../reference/typeParameterAsBaseClass.js     |  2 +-
 .../reference/typeParameterAsBaseType.js      |  4 +-
 .../reference/typeParameterExtendingUnion1.js |  4 +-
 .../reference/typeParameterExtendingUnion2.js |  4 +-
 .../baselines/reference/typeRelationships.js  |  2 +-
 .../baselines/reference/typeValueConflict1.js |  2 +-
 .../baselines/reference/typeValueConflict2.js |  4 +-
 tests/baselines/reference/typeofClass2.js     |  2 +-
 .../typesWithSpecializedCallSignatures.js     |  4 +-
 ...typesWithSpecializedConstructSignatures.js |  4 +-
 tests/baselines/reference/undeclaredBase.js   |  2 +-
 .../undefinedIsSubtypeOfEverything.js         | 44 ++++-----
 .../baselines/reference/underscoreMapFirst.js |  2 +-
 .../underscoreThisInDerivedClass01.js         |  2 +-
 .../underscoreThisInDerivedClass02.js         |  2 +-
 .../reference/unionTypeEquivalence.js         |  2 +-
 .../reference/unionTypeFromArrayLiteral.js    |  4 +-
 .../reference/unionTypesAssignability.js      |  4 +-
 .../reference/unspecializedConstraints.js     |  2 +-
 ...untypedFunctionCallsWithTypeParameters1.js |  2 +-
 .../reference/unusedClassesinNamespace4.js    |  2 +-
 .../unusedIdentifiersConsolidated1.js         |  2 +-
 585 files changed, 1227 insertions(+), 1225 deletions(-)

diff --git a/src/compiler/transformers/es2015.ts b/src/compiler/transformers/es2015.ts
index 5dae1da7b74..a4d8df6b8d4 100644
--- a/src/compiler/transformers/es2015.ts
+++ b/src/compiler/transformers/es2015.ts
@@ -882,7 +882,10 @@ namespace ts {
 
             }
 
-            const superCaptureStatus = declareOrCaptureOrReturnThisForConstructorIfNeeded(statements, constructor, !!extendsClauseElement, hasSynthesizedSuper, statementOffset);
+            // determine whether the class is known syntactically to be a derived class (e.g. a
+            // class that extends a value that is not syntactically known to be `null`).
+            const isDerivedClass = extendsClauseElement && skipOuterExpressions(extendsClauseElement.expression).kind !== SyntaxKind.NullKeyword;
+            const superCaptureStatus = declareOrCaptureOrReturnThisForConstructorIfNeeded(statements, constructor, isDerivedClass, hasSynthesizedSuper, statementOffset);
 
             // The last statement expression was replaced. Skip it.
             if (superCaptureStatus === SuperCaptureResult.ReplaceSuperCapture || superCaptureStatus === SuperCaptureResult.ReplaceWithReturn) {
@@ -899,7 +902,7 @@ namespace ts {
 
             // Return `_this` unless we're sure enough that it would be pointless to add a return statement.
             // If there's a constructor that we can tell returns in enough places, then we *do not* want to add a return.
-            if (extendsClauseElement
+            if (isDerivedClass
                 && superCaptureStatus !== SuperCaptureResult.ReplaceWithReturn
                 && !(constructor && isSufficientlyCoveredByReturnStatements(constructor.body))) {
                 statements.push(
@@ -963,11 +966,11 @@ namespace ts {
         function declareOrCaptureOrReturnThisForConstructorIfNeeded(
                     statements: Statement[],
                     ctor: ConstructorDeclaration | undefined,
-                    hasExtendsClause: boolean,
+                    isDerivedClass: boolean,
                     hasSynthesizedSuper: boolean,
                     statementOffset: number) {
             // If this isn't a derived class, just capture 'this' for arrow functions if necessary.
-            if (!hasExtendsClause) {
+            if (!isDerivedClass) {
                 if (ctor) {
                     addCaptureThisForNodeIfNeeded(statements, ctor);
                 }
@@ -1047,7 +1050,7 @@ namespace ts {
             }
 
             // Perform the capture.
-            captureThisForNode(statements, ctor, superCallExpression, firstStatement);
+            captureThisForNode(statements, ctor, superCallExpression || createActualThis(), firstStatement);
 
             // If we're actually replacing the original statement, we need to signal this to the caller.
             if (superCallExpression) {
@@ -1057,15 +1060,25 @@ namespace ts {
             return SuperCaptureResult.NoReplacement;
         }
 
+        function createActualThis() {
+            return setEmitFlags(createThis(), EmitFlags.NoSubstitution);
+        }
+
         function createDefaultSuperCallOrThis() {
-            const actualThis = createThis();
-            setEmitFlags(actualThis, EmitFlags.NoSubstitution);
-            const superCall = createFunctionApply(
-                createIdentifier("_super"),
-                actualThis,
-                createIdentifier("arguments"),
+            return createLogicalOr(
+                createLogicalAnd(
+                    createStrictInequality(
+                        createIdentifier("_super"),
+                        createNull()
+                    ),
+                    createFunctionApply(
+                        createIdentifier("_super"),
+                        createActualThis(),
+                        createIdentifier("arguments")
+                    )
+                ),
+                createActualThis()
             );
-            return createLogicalOr(superCall, actualThis);
         }
 
         /**
diff --git a/tests/baselines/reference/ExportClassWithAccessibleTypesInTypeParameterConstraintsClassHeritageListMemberTypeAnnotations.js b/tests/baselines/reference/ExportClassWithAccessibleTypesInTypeParameterConstraintsClassHeritageListMemberTypeAnnotations.js
index ec0ed5494a4..a42424b36bb 100644
--- a/tests/baselines/reference/ExportClassWithAccessibleTypesInTypeParameterConstraintsClassHeritageListMemberTypeAnnotations.js
+++ b/tests/baselines/reference/ExportClassWithAccessibleTypesInTypeParameterConstraintsClassHeritageListMemberTypeAnnotations.js
@@ -38,7 +38,7 @@ var A;
     var Point3d = (function (_super) {
         __extends(Point3d, _super);
         function Point3d() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Point3d;
     }(Point));
diff --git a/tests/baselines/reference/ExportClassWithInaccessibleTypeInTypeParameterConstraint.js b/tests/baselines/reference/ExportClassWithInaccessibleTypeInTypeParameterConstraint.js
index bae9593fb98..12d16837a57 100644
--- a/tests/baselines/reference/ExportClassWithInaccessibleTypeInTypeParameterConstraint.js
+++ b/tests/baselines/reference/ExportClassWithInaccessibleTypeInTypeParameterConstraint.js
@@ -41,7 +41,7 @@ var A;
     var Point3d = (function (_super) {
         __extends(Point3d, _super);
         function Point3d() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Point3d;
     }(Point));
diff --git a/tests/baselines/reference/abstractClassInLocalScope.js b/tests/baselines/reference/abstractClassInLocalScope.js
index db5144be399..455fd716889 100644
--- a/tests/baselines/reference/abstractClassInLocalScope.js
+++ b/tests/baselines/reference/abstractClassInLocalScope.js
@@ -22,7 +22,7 @@ var __extends = (this && this.__extends) || function (d, b) {
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
diff --git a/tests/baselines/reference/abstractClassInLocalScopeIsAbstract.js b/tests/baselines/reference/abstractClassInLocalScopeIsAbstract.js
index 1b3e11cfa32..9c7cca30692 100644
--- a/tests/baselines/reference/abstractClassInLocalScopeIsAbstract.js
+++ b/tests/baselines/reference/abstractClassInLocalScopeIsAbstract.js
@@ -22,7 +22,7 @@ var __extends = (this && this.__extends) || function (d, b) {
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
diff --git a/tests/baselines/reference/abstractProperty.js b/tests/baselines/reference/abstractProperty.js
index fb7deaa09dd..d4ef48ac84f 100644
--- a/tests/baselines/reference/abstractProperty.js
+++ b/tests/baselines/reference/abstractProperty.js
@@ -35,7 +35,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.raw = "edge";
         _this.ro = "readonly please";
         return _this;
diff --git a/tests/baselines/reference/abstractPropertyNegative.js b/tests/baselines/reference/abstractPropertyNegative.js
index bebf9026a0e..c5e12a3cfa0 100644
--- a/tests/baselines/reference/abstractPropertyNegative.js
+++ b/tests/baselines/reference/abstractPropertyNegative.js
@@ -57,7 +57,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.ro = "readonly please";
         return _this;
     }
@@ -78,7 +78,7 @@ var WrongTypeProperty = (function () {
 var WrongTypePropertyImpl = (function (_super) {
     __extends(WrongTypePropertyImpl, _super);
     function WrongTypePropertyImpl() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.num = "nope, wrong";
         return _this;
     }
@@ -92,7 +92,7 @@ var WrongTypeAccessor = (function () {
 var WrongTypeAccessorImpl = (function (_super) {
     __extends(WrongTypeAccessorImpl, _super);
     function WrongTypeAccessorImpl() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(WrongTypeAccessorImpl.prototype, "num", {
         get: function () { return "nope, wrong"; },
@@ -104,7 +104,7 @@ var WrongTypeAccessorImpl = (function (_super) {
 var WrongTypeAccessorImpl2 = (function (_super) {
     __extends(WrongTypeAccessorImpl2, _super);
     function WrongTypeAccessorImpl2() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.num = "nope, wrong";
         return _this;
     }
diff --git a/tests/baselines/reference/accessors_spec_section-4.5_inference.js b/tests/baselines/reference/accessors_spec_section-4.5_inference.js
index dbaeec1f688..efafc978bee 100644
--- a/tests/baselines/reference/accessors_spec_section-4.5_inference.js
+++ b/tests/baselines/reference/accessors_spec_section-4.5_inference.js
@@ -38,7 +38,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/aliasUsageInAccessorsOfClass.js b/tests/baselines/reference/aliasUsageInAccessorsOfClass.js
index 8b60ed8e76d..1c2bed21529 100644
--- a/tests/baselines/reference/aliasUsageInAccessorsOfClass.js
+++ b/tests/baselines/reference/aliasUsageInAccessorsOfClass.js
@@ -46,7 +46,7 @@ var Backbone = require("./aliasUsage1_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
diff --git a/tests/baselines/reference/aliasUsageInArray.js b/tests/baselines/reference/aliasUsageInArray.js
index bf573aa9abb..fb1a37b2e93 100644
--- a/tests/baselines/reference/aliasUsageInArray.js
+++ b/tests/baselines/reference/aliasUsageInArray.js
@@ -40,7 +40,7 @@ var Backbone = require("./aliasUsageInArray_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
diff --git a/tests/baselines/reference/aliasUsageInFunctionExpression.js b/tests/baselines/reference/aliasUsageInFunctionExpression.js
index 49bdd493aac..a611efa37bf 100644
--- a/tests/baselines/reference/aliasUsageInFunctionExpression.js
+++ b/tests/baselines/reference/aliasUsageInFunctionExpression.js
@@ -39,7 +39,7 @@ var Backbone = require("./aliasUsageInFunctionExpression_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
diff --git a/tests/baselines/reference/aliasUsageInGenericFunction.js b/tests/baselines/reference/aliasUsageInGenericFunction.js
index dc3a8a88bab..033d206a4a5 100644
--- a/tests/baselines/reference/aliasUsageInGenericFunction.js
+++ b/tests/baselines/reference/aliasUsageInGenericFunction.js
@@ -43,7 +43,7 @@ var Backbone = require("./aliasUsageInGenericFunction_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
diff --git a/tests/baselines/reference/aliasUsageInIndexerOfClass.js b/tests/baselines/reference/aliasUsageInIndexerOfClass.js
index cb7ad3027ca..fe79dcd655f 100644
--- a/tests/baselines/reference/aliasUsageInIndexerOfClass.js
+++ b/tests/baselines/reference/aliasUsageInIndexerOfClass.js
@@ -45,7 +45,7 @@ var Backbone = require("./aliasUsageInIndexerOfClass_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
diff --git a/tests/baselines/reference/aliasUsageInObjectLiteral.js b/tests/baselines/reference/aliasUsageInObjectLiteral.js
index 81e3e621e85..236397053a4 100644
--- a/tests/baselines/reference/aliasUsageInObjectLiteral.js
+++ b/tests/baselines/reference/aliasUsageInObjectLiteral.js
@@ -40,7 +40,7 @@ var Backbone = require("./aliasUsageInObjectLiteral_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
diff --git a/tests/baselines/reference/aliasUsageInOrExpression.js b/tests/baselines/reference/aliasUsageInOrExpression.js
index 4faa41dd034..452566010e5 100644
--- a/tests/baselines/reference/aliasUsageInOrExpression.js
+++ b/tests/baselines/reference/aliasUsageInOrExpression.js
@@ -43,7 +43,7 @@ var Backbone = require("./aliasUsageInOrExpression_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
diff --git a/tests/baselines/reference/aliasUsageInTypeArgumentOfExtendsClause.js b/tests/baselines/reference/aliasUsageInTypeArgumentOfExtendsClause.js
index 2cf4aefab6c..2bfc7ce3c3c 100644
--- a/tests/baselines/reference/aliasUsageInTypeArgumentOfExtendsClause.js
+++ b/tests/baselines/reference/aliasUsageInTypeArgumentOfExtendsClause.js
@@ -43,7 +43,7 @@ var Backbone = require("./aliasUsageInTypeArgumentOfExtendsClause_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
@@ -64,7 +64,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = moduleA;
         return _this;
     }
diff --git a/tests/baselines/reference/aliasUsageInVarAssignment.js b/tests/baselines/reference/aliasUsageInVarAssignment.js
index 80bb2dca20e..b0b40dca969 100644
--- a/tests/baselines/reference/aliasUsageInVarAssignment.js
+++ b/tests/baselines/reference/aliasUsageInVarAssignment.js
@@ -39,7 +39,7 @@ var Backbone = require("./aliasUsageInVarAssignment_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
diff --git a/tests/baselines/reference/ambiguousOverloadResolution.js b/tests/baselines/reference/ambiguousOverloadResolution.js
index 01002792921..5cf216dcd38 100644
--- a/tests/baselines/reference/ambiguousOverloadResolution.js
+++ b/tests/baselines/reference/ambiguousOverloadResolution.js
@@ -22,7 +22,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/apparentTypeSubtyping.js b/tests/baselines/reference/apparentTypeSubtyping.js
index 6ca9d343a72..517e7da75cc 100644
--- a/tests/baselines/reference/apparentTypeSubtyping.js
+++ b/tests/baselines/reference/apparentTypeSubtyping.js
@@ -38,7 +38,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -51,7 +51,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/apparentTypeSupertype.js b/tests/baselines/reference/apparentTypeSupertype.js
index c6d3378872e..42043b0bda9 100644
--- a/tests/baselines/reference/apparentTypeSupertype.js
+++ b/tests/baselines/reference/apparentTypeSupertype.js
@@ -28,7 +28,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/arrayAssignmentTest1.js b/tests/baselines/reference/arrayAssignmentTest1.js
index a887203cd5e..18a0aeb77da 100644
--- a/tests/baselines/reference/arrayAssignmentTest1.js
+++ b/tests/baselines/reference/arrayAssignmentTest1.js
@@ -101,7 +101,7 @@ var C1 = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C2.prototype.C2M1 = function () { return null; };
     return C2;
diff --git a/tests/baselines/reference/arrayAssignmentTest2.js b/tests/baselines/reference/arrayAssignmentTest2.js
index d82dedff29d..4782542f232 100644
--- a/tests/baselines/reference/arrayAssignmentTest2.js
+++ b/tests/baselines/reference/arrayAssignmentTest2.js
@@ -75,7 +75,7 @@ var C1 = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C2.prototype.C2M1 = function () { return null; };
     return C2;
diff --git a/tests/baselines/reference/arrayBestCommonTypes.js b/tests/baselines/reference/arrayBestCommonTypes.js
index b7ddaa5d6da..fd0ea619bb0 100644
--- a/tests/baselines/reference/arrayBestCommonTypes.js
+++ b/tests/baselines/reference/arrayBestCommonTypes.js
@@ -128,7 +128,7 @@ var EmptyTypes;
     var derived = (function (_super) {
         __extends(derived, _super);
         function derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return derived;
     }(base));
@@ -187,7 +187,7 @@ var NonEmptyTypes;
     var derived = (function (_super) {
         __extends(derived, _super);
         function derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return derived;
     }(base));
diff --git a/tests/baselines/reference/arrayLiteralTypeInference.js b/tests/baselines/reference/arrayLiteralTypeInference.js
index 919d3a5e922..8173747139c 100644
--- a/tests/baselines/reference/arrayLiteralTypeInference.js
+++ b/tests/baselines/reference/arrayLiteralTypeInference.js
@@ -65,14 +65,14 @@ var Action = (function () {
 var ActionA = (function (_super) {
     __extends(ActionA, _super);
     function ActionA() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ActionA;
 }(Action));
 var ActionB = (function (_super) {
     __extends(ActionB, _super);
     function ActionB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ActionB;
 }(Action));
diff --git a/tests/baselines/reference/arrayLiterals.js b/tests/baselines/reference/arrayLiterals.js
index 530cdedec73..68c886e3c04 100644
--- a/tests/baselines/reference/arrayLiterals.js
+++ b/tests/baselines/reference/arrayLiterals.js
@@ -70,7 +70,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived1;
 }(Base));
@@ -78,7 +78,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/arrayLiteralsWithRecursiveGenerics.js b/tests/baselines/reference/arrayLiteralsWithRecursiveGenerics.js
index c0f320ac1e5..947186e4e6f 100644
--- a/tests/baselines/reference/arrayLiteralsWithRecursiveGenerics.js
+++ b/tests/baselines/reference/arrayLiteralsWithRecursiveGenerics.js
@@ -39,7 +39,7 @@ var List = (function () {
 var DerivedList = (function (_super) {
     __extends(DerivedList, _super);
     function DerivedList() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return DerivedList;
 }(List));
diff --git a/tests/baselines/reference/arrayOfSubtypeIsAssignableToReadonlyArray.js b/tests/baselines/reference/arrayOfSubtypeIsAssignableToReadonlyArray.js
index d1d75e8041c..4cd45282674 100644
--- a/tests/baselines/reference/arrayOfSubtypeIsAssignableToReadonlyArray.js
+++ b/tests/baselines/reference/arrayOfSubtypeIsAssignableToReadonlyArray.js
@@ -33,14 +33,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(Array));
diff --git a/tests/baselines/reference/assignmentCompatWithCallSignatures3.js b/tests/baselines/reference/assignmentCompatWithCallSignatures3.js
index c5a1f415437..de4624a8679 100644
--- a/tests/baselines/reference/assignmentCompatWithCallSignatures3.js
+++ b/tests/baselines/reference/assignmentCompatWithCallSignatures3.js
@@ -114,21 +114,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/assignmentCompatWithCallSignatures4.js b/tests/baselines/reference/assignmentCompatWithCallSignatures4.js
index 58faf663ea8..f47d201b67e 100644
--- a/tests/baselines/reference/assignmentCompatWithCallSignatures4.js
+++ b/tests/baselines/reference/assignmentCompatWithCallSignatures4.js
@@ -115,21 +115,21 @@ var Errors;
     var Derived = (function (_super) {
         __extends(Derived, _super);
         function Derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived;
     }(Base));
     var Derived2 = (function (_super) {
         __extends(Derived2, _super);
         function Derived2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived2;
     }(Derived));
     var OtherDerived = (function (_super) {
         __extends(OtherDerived, _super);
         function OtherDerived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return OtherDerived;
     }(Base));
diff --git a/tests/baselines/reference/assignmentCompatWithCallSignatures5.js b/tests/baselines/reference/assignmentCompatWithCallSignatures5.js
index 87506cad08f..90a9ce68428 100644
--- a/tests/baselines/reference/assignmentCompatWithCallSignatures5.js
+++ b/tests/baselines/reference/assignmentCompatWithCallSignatures5.js
@@ -80,21 +80,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/assignmentCompatWithCallSignatures6.js b/tests/baselines/reference/assignmentCompatWithCallSignatures6.js
index 2c05d5960b2..f970f31cd1f 100644
--- a/tests/baselines/reference/assignmentCompatWithCallSignatures6.js
+++ b/tests/baselines/reference/assignmentCompatWithCallSignatures6.js
@@ -57,21 +57,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/assignmentCompatWithConstructSignatures3.js b/tests/baselines/reference/assignmentCompatWithConstructSignatures3.js
index 76ad53e4e05..e788a20089f 100644
--- a/tests/baselines/reference/assignmentCompatWithConstructSignatures3.js
+++ b/tests/baselines/reference/assignmentCompatWithConstructSignatures3.js
@@ -114,21 +114,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/assignmentCompatWithConstructSignatures4.js b/tests/baselines/reference/assignmentCompatWithConstructSignatures4.js
index f516df153c6..bec6f0dd265 100644
--- a/tests/baselines/reference/assignmentCompatWithConstructSignatures4.js
+++ b/tests/baselines/reference/assignmentCompatWithConstructSignatures4.js
@@ -115,21 +115,21 @@ var Errors;
     var Derived = (function (_super) {
         __extends(Derived, _super);
         function Derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived;
     }(Base));
     var Derived2 = (function (_super) {
         __extends(Derived2, _super);
         function Derived2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived2;
     }(Derived));
     var OtherDerived = (function (_super) {
         __extends(OtherDerived, _super);
         function OtherDerived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return OtherDerived;
     }(Base));
diff --git a/tests/baselines/reference/assignmentCompatWithConstructSignatures5.js b/tests/baselines/reference/assignmentCompatWithConstructSignatures5.js
index ef7de7f011b..98ab16721ed 100644
--- a/tests/baselines/reference/assignmentCompatWithConstructSignatures5.js
+++ b/tests/baselines/reference/assignmentCompatWithConstructSignatures5.js
@@ -80,21 +80,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/assignmentCompatWithConstructSignatures6.js b/tests/baselines/reference/assignmentCompatWithConstructSignatures6.js
index 3d58ae707a5..3716cc120eb 100644
--- a/tests/baselines/reference/assignmentCompatWithConstructSignatures6.js
+++ b/tests/baselines/reference/assignmentCompatWithConstructSignatures6.js
@@ -57,21 +57,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/assignmentCompatWithNumericIndexer.js b/tests/baselines/reference/assignmentCompatWithNumericIndexer.js
index 37160506683..82f71a9a905 100644
--- a/tests/baselines/reference/assignmentCompatWithNumericIndexer.js
+++ b/tests/baselines/reference/assignmentCompatWithNumericIndexer.js
@@ -72,7 +72,7 @@ var Generics;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
diff --git a/tests/baselines/reference/assignmentCompatWithNumericIndexer3.js b/tests/baselines/reference/assignmentCompatWithNumericIndexer3.js
index 2e6ecd72741..6b8654f4153 100644
--- a/tests/baselines/reference/assignmentCompatWithNumericIndexer3.js
+++ b/tests/baselines/reference/assignmentCompatWithNumericIndexer3.js
@@ -59,7 +59,7 @@ b = a; // ok
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A));
diff --git a/tests/baselines/reference/assignmentCompatWithObjectMembers4.js b/tests/baselines/reference/assignmentCompatWithObjectMembers4.js
index 2cc2510c8da..3d6ee83e467 100644
--- a/tests/baselines/reference/assignmentCompatWithObjectMembers4.js
+++ b/tests/baselines/reference/assignmentCompatWithObjectMembers4.js
@@ -108,14 +108,14 @@ var OnlyDerived;
     var Derived = (function (_super) {
         __extends(Derived, _super);
         function Derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived;
     }(Base));
     var Derived2 = (function (_super) {
         __extends(Derived2, _super);
         function Derived2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived2;
     }(Base));
@@ -167,14 +167,14 @@ var WithBase;
     var Derived = (function (_super) {
         __extends(Derived, _super);
         function Derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived;
     }(Base));
     var Derived2 = (function (_super) {
         __extends(Derived2, _super);
         function Derived2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived2;
     }(Base));
diff --git a/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality.js b/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality.js
index 3b12701b3d9..bdef4c0a488 100644
--- a/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality.js
+++ b/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality.js
@@ -103,14 +103,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
diff --git a/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality2.js b/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality2.js
index f965d18e2ce..496a5b7bdfa 100644
--- a/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality2.js
+++ b/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality2.js
@@ -105,14 +105,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
diff --git a/tests/baselines/reference/assignmentCompatWithStringIndexer.js b/tests/baselines/reference/assignmentCompatWithStringIndexer.js
index 8d081c90794..6c4fe424d1b 100644
--- a/tests/baselines/reference/assignmentCompatWithStringIndexer.js
+++ b/tests/baselines/reference/assignmentCompatWithStringIndexer.js
@@ -82,7 +82,7 @@ var Generics;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
@@ -93,7 +93,7 @@ var Generics;
     var B2 = (function (_super) {
         __extends(B2, _super);
         function B2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B2;
     }(A));
diff --git a/tests/baselines/reference/asyncImportedPromise_es5.js b/tests/baselines/reference/asyncImportedPromise_es5.js
index 641b8e0381f..7aab30f9fa0 100644
--- a/tests/baselines/reference/asyncImportedPromise_es5.js
+++ b/tests/baselines/reference/asyncImportedPromise_es5.js
@@ -19,7 +19,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var Task = (function (_super) {
     __extends(Task, _super);
     function Task() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Task;
 }(Promise));
diff --git a/tests/baselines/reference/asyncMethodWithSuper_es5.js b/tests/baselines/reference/asyncMethodWithSuper_es5.js
index 235f2763f9f..c68b1ed036f 100644
--- a/tests/baselines/reference/asyncMethodWithSuper_es5.js
+++ b/tests/baselines/reference/asyncMethodWithSuper_es5.js
@@ -61,7 +61,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     // async method with only call/get on 'super' does not require a binding
     B.prototype.simple = function () {
diff --git a/tests/baselines/reference/asyncQualifiedReturnType_es5.js b/tests/baselines/reference/asyncQualifiedReturnType_es5.js
index dd54f6ee833..3cae9ea6b56 100644
--- a/tests/baselines/reference/asyncQualifiedReturnType_es5.js
+++ b/tests/baselines/reference/asyncQualifiedReturnType_es5.js
@@ -13,7 +13,7 @@ var X;
     var MyPromise = (function (_super) {
         __extends(MyPromise, _super);
         function MyPromise() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return MyPromise;
     }(Promise));
diff --git a/tests/baselines/reference/awaitClassExpression_es5.js b/tests/baselines/reference/awaitClassExpression_es5.js
index b207ba08f8d..9cb8ce22f63 100644
--- a/tests/baselines/reference/awaitClassExpression_es5.js
+++ b/tests/baselines/reference/awaitClassExpression_es5.js
@@ -17,7 +17,7 @@ function func() {
                     _a = function (_super) {
                         __extends(D, _super);
                         function D() {
-                            return _super.apply(this, arguments) || this;
+                            return _super !== null && _super.apply(this, arguments) || this;
                         }
                         return D;
                     };
diff --git a/tests/baselines/reference/baseIndexSignatureResolution.js b/tests/baselines/reference/baseIndexSignatureResolution.js
index 7e922cf83b2..0f28011b2b2 100644
--- a/tests/baselines/reference/baseIndexSignatureResolution.js
+++ b/tests/baselines/reference/baseIndexSignatureResolution.js
@@ -38,7 +38,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/baseTypeOrderChecking.js b/tests/baselines/reference/baseTypeOrderChecking.js
index ec96b80a999..623f07930f1 100644
--- a/tests/baselines/reference/baseTypeOrderChecking.js
+++ b/tests/baselines/reference/baseTypeOrderChecking.js
@@ -51,7 +51,7 @@ var Class1 = (function () {
 var Class2 = (function (_super) {
     __extends(Class2, _super);
     function Class2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Class2;
 }(Class1));
@@ -63,7 +63,7 @@ var Class3 = (function () {
 var Class4 = (function (_super) {
     __extends(Class4, _super);
     function Class4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Class4;
 }(Class3));
diff --git a/tests/baselines/reference/baseTypeWrappingInstantiationChain.js b/tests/baselines/reference/baseTypeWrappingInstantiationChain.js
index 5f8dcbd0e10..6b017d1d60a 100644
--- a/tests/baselines/reference/baseTypeWrappingInstantiationChain.js
+++ b/tests/baselines/reference/baseTypeWrappingInstantiationChain.js
@@ -41,7 +41,7 @@ var CBaseBase = (function () {
 var CBase = (function (_super) {
     __extends(CBase, _super);
     function CBase() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return CBase;
 }(CBaseBase));
@@ -59,7 +59,7 @@ var Wrapper = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.works = function () {
         new CBaseBase(this);
diff --git a/tests/baselines/reference/bases.js b/tests/baselines/reference/bases.js
index 6b73eb9556b..b803423fd6f 100644
--- a/tests/baselines/reference/bases.js
+++ b/tests/baselines/reference/bases.js
@@ -36,7 +36,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        var _this;
+        var _this = this;
         _this.x;
         any;
         return _this;
diff --git a/tests/baselines/reference/bestCommonTypeOfConditionalExpressions.js b/tests/baselines/reference/bestCommonTypeOfConditionalExpressions.js
index 6d0f19dd37d..ee40ccaf724 100644
--- a/tests/baselines/reference/bestCommonTypeOfConditionalExpressions.js
+++ b/tests/baselines/reference/bestCommonTypeOfConditionalExpressions.js
@@ -44,14 +44,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/bestCommonTypeOfConditionalExpressions2.js b/tests/baselines/reference/bestCommonTypeOfConditionalExpressions2.js
index 2e2d0bcb1e2..ce14274b531 100644
--- a/tests/baselines/reference/bestCommonTypeOfConditionalExpressions2.js
+++ b/tests/baselines/reference/bestCommonTypeOfConditionalExpressions2.js
@@ -40,14 +40,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/bestCommonTypeOfTuple2.js b/tests/baselines/reference/bestCommonTypeOfTuple2.js
index 928909f4c38..38c2b498929 100644
--- a/tests/baselines/reference/bestCommonTypeOfTuple2.js
+++ b/tests/baselines/reference/bestCommonTypeOfTuple2.js
@@ -46,7 +46,7 @@ var E = (function () {
 var F = (function (_super) {
     __extends(F, _super);
     function F() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return F;
 }(C));
@@ -59,7 +59,7 @@ var C1 = (function () {
 var D1 = (function (_super) {
     __extends(D1, _super);
     function D1() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.i = "bar";
         return _this;
     }
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance2.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance2.js
index 0ae7648c7f9..733c9b744fd 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance2.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance2.js
@@ -84,21 +84,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance3.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance3.js
index 7a7791280ad..c07edf25e4e 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance3.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance3.js
@@ -131,21 +131,21 @@ var Errors;
     var Derived = (function (_super) {
         __extends(Derived, _super);
         function Derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived;
     }(Base));
     var Derived2 = (function (_super) {
         __extends(Derived2, _super);
         function Derived2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived2;
     }(Derived));
     var OtherDerived = (function (_super) {
         __extends(OtherDerived, _super);
         function OtherDerived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return OtherDerived;
     }(Base));
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance4.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance4.js
index 19d66ce8d46..2e0833a2b30 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance4.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance4.js
@@ -64,21 +64,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance5.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance5.js
index 1c53de5d26e..d7f79d37681 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance5.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance5.js
@@ -64,21 +64,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance6.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance6.js
index c42e36389ca..de5251be911 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance6.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance6.js
@@ -67,21 +67,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/castingTuple.js b/tests/baselines/reference/castingTuple.js
index f0178dcbbf0..1dcc8a7b264 100644
--- a/tests/baselines/reference/castingTuple.js
+++ b/tests/baselines/reference/castingTuple.js
@@ -59,7 +59,7 @@ var D = (function () {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E;
 }(A));
@@ -67,7 +67,7 @@ var E = (function (_super) {
 var F = (function (_super) {
     __extends(F, _super);
     function F() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return F;
 }(A));
diff --git a/tests/baselines/reference/chainedAssignment3.js b/tests/baselines/reference/chainedAssignment3.js
index 3857867043c..0fc896ab83f 100644
--- a/tests/baselines/reference/chainedAssignment3.js
+++ b/tests/baselines/reference/chainedAssignment3.js
@@ -36,7 +36,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.js b/tests/baselines/reference/chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.js
index 26d341e1f6a..8d8d4e1e787 100644
--- a/tests/baselines/reference/chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.js
+++ b/tests/baselines/reference/chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.js
@@ -42,14 +42,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(B));
diff --git a/tests/baselines/reference/checkSuperCallBeforeThisAccessing2.js b/tests/baselines/reference/checkSuperCallBeforeThisAccessing2.js
index 95b34f27b68..a74c0015f89 100644
--- a/tests/baselines/reference/checkSuperCallBeforeThisAccessing2.js
+++ b/tests/baselines/reference/checkSuperCallBeforeThisAccessing2.js
@@ -24,7 +24,7 @@ var Based = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this;
+        var _this = this;
         _this.x = 100;
         _this = _super.call(this) || this;
         _this.x = 10;
diff --git a/tests/baselines/reference/checkSuperCallBeforeThisAccessing3.js b/tests/baselines/reference/checkSuperCallBeforeThisAccessing3.js
index 0e882f71fdb..ebb0a6d7685 100644
--- a/tests/baselines/reference/checkSuperCallBeforeThisAccessing3.js
+++ b/tests/baselines/reference/checkSuperCallBeforeThisAccessing3.js
@@ -29,7 +29,7 @@ var Based = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this;
+        var _this = this;
         var innver = (function () {
             function innver() {
                 this.y = true;
diff --git a/tests/baselines/reference/checkSuperCallBeforeThisAccessing4.js b/tests/baselines/reference/checkSuperCallBeforeThisAccessing4.js
index 00f2ed22fbf..19a701d4e0e 100644
--- a/tests/baselines/reference/checkSuperCallBeforeThisAccessing4.js
+++ b/tests/baselines/reference/checkSuperCallBeforeThisAccessing4.js
@@ -33,7 +33,7 @@ var Based = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this;
+        var _this = this;
         (function () {
             _this; // No error
         });
diff --git a/tests/baselines/reference/checkSuperCallBeforeThisAccessing6.js b/tests/baselines/reference/checkSuperCallBeforeThisAccessing6.js
index 782e3236271..9468d817e23 100644
--- a/tests/baselines/reference/checkSuperCallBeforeThisAccessing6.js
+++ b/tests/baselines/reference/checkSuperCallBeforeThisAccessing6.js
@@ -28,7 +28,7 @@ var Base = (function () {
 var Super = (function (_super) {
     __extends(Super, _super);
     function Super() {
-        var _this;
+        var _this = this;
         (function () { return _this; }); // No Error
         _this = _super.call(this) || this;
         return _this;
diff --git a/tests/baselines/reference/checkSuperCallBeforeThisAccessing8.js b/tests/baselines/reference/checkSuperCallBeforeThisAccessing8.js
index 5dd3708a3bb..3c61f03eb46 100644
--- a/tests/baselines/reference/checkSuperCallBeforeThisAccessing8.js
+++ b/tests/baselines/reference/checkSuperCallBeforeThisAccessing8.js
@@ -28,7 +28,7 @@ var Base = (function () {
 var Super = (function (_super) {
     __extends(Super, _super);
     function Super() {
-        var _this;
+        var _this = this;
         var that = _this;
         _this = _super.call(this) || this;
         return _this;
diff --git a/tests/baselines/reference/circularImportAlias.js b/tests/baselines/reference/circularImportAlias.js
index 6fe5e604e57..42efa92f5ba 100644
--- a/tests/baselines/reference/circularImportAlias.js
+++ b/tests/baselines/reference/circularImportAlias.js
@@ -32,7 +32,7 @@ var B;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(B.a.C));
diff --git a/tests/baselines/reference/circularTypeofWithFunctionModule.js b/tests/baselines/reference/circularTypeofWithFunctionModule.js
index 1c38b9625e3..89c81d0df2a 100644
--- a/tests/baselines/reference/circularTypeofWithFunctionModule.js
+++ b/tests/baselines/reference/circularTypeofWithFunctionModule.js
@@ -31,7 +31,7 @@ function maker(value) {
     var Bar = (function (_super) {
         __extends(Bar, _super);
         function Bar() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Bar;
     }(Foo));
diff --git a/tests/baselines/reference/classAbstractConstructorAssignability.js b/tests/baselines/reference/classAbstractConstructorAssignability.js
index 35d9e75884f..a0ea721c1a8 100644
--- a/tests/baselines/reference/classAbstractConstructorAssignability.js
+++ b/tests/baselines/reference/classAbstractConstructorAssignability.js
@@ -28,14 +28,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(B));
diff --git a/tests/baselines/reference/classAbstractCrashedOnce.js b/tests/baselines/reference/classAbstractCrashedOnce.js
index fe23e60c94f..4ce3ec9a3a8 100644
--- a/tests/baselines/reference/classAbstractCrashedOnce.js
+++ b/tests/baselines/reference/classAbstractCrashedOnce.js
@@ -24,7 +24,7 @@ var foo = (function () {
 var bar = (function (_super) {
     __extends(bar, _super);
     function bar() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     bar.prototype.test = function () {
         this.
diff --git a/tests/baselines/reference/classAbstractExtends.js b/tests/baselines/reference/classAbstractExtends.js
index e899cb82d6d..4d2e5d2492d 100644
--- a/tests/baselines/reference/classAbstractExtends.js
+++ b/tests/baselines/reference/classAbstractExtends.js
@@ -31,28 +31,28 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(B));
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(B));
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.bar = function () { };
     return E;
diff --git a/tests/baselines/reference/classAbstractFactoryFunction.js b/tests/baselines/reference/classAbstractFactoryFunction.js
index 50e232a9fca..a7046ff159c 100644
--- a/tests/baselines/reference/classAbstractFactoryFunction.js
+++ b/tests/baselines/reference/classAbstractFactoryFunction.js
@@ -31,7 +31,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/classAbstractGeneric.js b/tests/baselines/reference/classAbstractGeneric.js
index 96df8f5f19e..0bb24e8c92c 100644
--- a/tests/baselines/reference/classAbstractGeneric.js
+++ b/tests/baselines/reference/classAbstractGeneric.js
@@ -39,28 +39,28 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A)); // error -- inherits abstract methods
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(A)); // error -- inherits abstract methods
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.foo = function () { return this.t; };
     return E;
@@ -68,7 +68,7 @@ var E = (function (_super) {
 var F = (function (_super) {
     __extends(F, _super);
     function F() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     F.prototype.bar = function (t) { };
     return F;
@@ -76,7 +76,7 @@ var F = (function (_super) {
 var G = (function (_super) {
     __extends(G, _super);
     function G() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     G.prototype.foo = function () { return this.t; };
     G.prototype.bar = function (t) { };
diff --git a/tests/baselines/reference/classAbstractInAModule.js b/tests/baselines/reference/classAbstractInAModule.js
index c6a9e206bcc..4081f23561c 100644
--- a/tests/baselines/reference/classAbstractInAModule.js
+++ b/tests/baselines/reference/classAbstractInAModule.js
@@ -24,7 +24,7 @@ var M;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
diff --git a/tests/baselines/reference/classAbstractInheritance.js b/tests/baselines/reference/classAbstractInheritance.js
index 297a80dd99c..8fe03d503b0 100644
--- a/tests/baselines/reference/classAbstractInheritance.js
+++ b/tests/baselines/reference/classAbstractInheritance.js
@@ -35,14 +35,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
@@ -54,42 +54,42 @@ var AA = (function () {
 var BB = (function (_super) {
     __extends(BB, _super);
     function BB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return BB;
 }(AA));
 var CC = (function (_super) {
     __extends(CC, _super);
     function CC() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return CC;
 }(AA));
 var DD = (function (_super) {
     __extends(DD, _super);
     function DD() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return DD;
 }(BB));
 var EE = (function (_super) {
     __extends(EE, _super);
     function EE() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return EE;
 }(BB));
 var FF = (function (_super) {
     __extends(FF, _super);
     function FF() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return FF;
 }(CC));
 var GG = (function (_super) {
     __extends(GG, _super);
     function GG() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return GG;
 }(CC));
diff --git a/tests/baselines/reference/classAbstractInstantiations1.js b/tests/baselines/reference/classAbstractInstantiations1.js
index 5abbb9c1baa..32e8f3e217f 100644
--- a/tests/baselines/reference/classAbstractInstantiations1.js
+++ b/tests/baselines/reference/classAbstractInstantiations1.js
@@ -41,14 +41,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(B));
diff --git a/tests/baselines/reference/classAbstractInstantiations2.js b/tests/baselines/reference/classAbstractInstantiations2.js
index dea4c744ae0..666a3bc2db2 100644
--- a/tests/baselines/reference/classAbstractInstantiations2.js
+++ b/tests/baselines/reference/classAbstractInstantiations2.js
@@ -82,21 +82,21 @@ new x; // okay -- undefined behavior at runtime
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(B)); // error -- not declared abstract
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(B)); // okay
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.bar = function () { return 1; };
     return E;
@@ -104,7 +104,7 @@ var E = (function (_super) {
 var F = (function (_super) {
     __extends(F, _super);
     function F() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     F.prototype.bar = function () { return 2; };
     return F;
diff --git a/tests/baselines/reference/classAbstractOverrideWithAbstract.js b/tests/baselines/reference/classAbstractOverrideWithAbstract.js
index 4ecebdf7b32..efa1dfcefba 100644
--- a/tests/baselines/reference/classAbstractOverrideWithAbstract.js
+++ b/tests/baselines/reference/classAbstractOverrideWithAbstract.js
@@ -38,7 +38,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -51,7 +51,7 @@ var AA = (function () {
 var BB = (function (_super) {
     __extends(BB, _super);
     function BB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     BB.prototype.bar = function () { };
     return BB;
@@ -59,14 +59,14 @@ var BB = (function (_super) {
 var CC = (function (_super) {
     __extends(CC, _super);
     function CC() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return CC;
 }(BB)); // error
 var DD = (function (_super) {
     __extends(DD, _super);
     function DD() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     DD.prototype.foo = function () { };
     return DD;
diff --git a/tests/baselines/reference/classAbstractSuperCalls.js b/tests/baselines/reference/classAbstractSuperCalls.js
index 0197f48a429..c246844b9b5 100644
--- a/tests/baselines/reference/classAbstractSuperCalls.js
+++ b/tests/baselines/reference/classAbstractSuperCalls.js
@@ -42,7 +42,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.bar = function () { _super.prototype.foo.call(this); };
     B.prototype.baz = function () { return this.foo; };
@@ -51,7 +51,7 @@ var B = (function (_super) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.foo = function () { return 2; };
     C.prototype.qux = function () { return _super.prototype.foo.call(this) || _super.prototype.foo; }; // 2 errors, foo is abstract
@@ -68,7 +68,7 @@ var AA = (function () {
 var BB = (function (_super) {
     __extends(BB, _super);
     function BB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return BB;
 }(AA));
diff --git a/tests/baselines/reference/classAbstractUsingAbstractMethod1.js b/tests/baselines/reference/classAbstractUsingAbstractMethod1.js
index 74b5d62aaf5..f5e0c7679d8 100644
--- a/tests/baselines/reference/classAbstractUsingAbstractMethod1.js
+++ b/tests/baselines/reference/classAbstractUsingAbstractMethod1.js
@@ -31,7 +31,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.foo = function () { return 1; };
     return B;
@@ -39,7 +39,7 @@ var B = (function (_super) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/classAbstractUsingAbstractMethods2.js b/tests/baselines/reference/classAbstractUsingAbstractMethods2.js
index 25cf1a307c7..028516efb9e 100644
--- a/tests/baselines/reference/classAbstractUsingAbstractMethods2.js
+++ b/tests/baselines/reference/classAbstractUsingAbstractMethods2.js
@@ -41,21 +41,21 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.foo = function () { };
     return D;
@@ -63,7 +63,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.foo = function () { };
     return E;
@@ -76,21 +76,21 @@ var AA = (function () {
 var BB = (function (_super) {
     __extends(BB, _super);
     function BB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return BB;
 }(AA));
 var CC = (function (_super) {
     __extends(CC, _super);
     function CC() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return CC;
 }(AA));
 var DD = (function (_super) {
     __extends(DD, _super);
     function DD() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     DD.prototype.foo = function () { };
     return DD;
diff --git a/tests/baselines/reference/classConstructorAccessibility4.js b/tests/baselines/reference/classConstructorAccessibility4.js
index 4772ac68d11..c0d4622f8ea 100644
--- a/tests/baselines/reference/classConstructorAccessibility4.js
+++ b/tests/baselines/reference/classConstructorAccessibility4.js
@@ -51,7 +51,7 @@ var A = (function () {
         var C = (function (_super) {
             __extends(C, _super);
             function C() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return C;
         }(A));
@@ -73,7 +73,7 @@ var D = (function () {
         var F = (function (_super) {
             __extends(F, _super);
             function F() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return F;
         }(D));
diff --git a/tests/baselines/reference/classConstructorAccessibility5.js b/tests/baselines/reference/classConstructorAccessibility5.js
index d658349c2a5..9d140e41987 100644
--- a/tests/baselines/reference/classConstructorAccessibility5.js
+++ b/tests/baselines/reference/classConstructorAccessibility5.js
@@ -25,7 +25,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.make = function () { new Base(); }; // ok
     return Derived;
diff --git a/tests/baselines/reference/classDeclarationMergedInModuleWithContinuation.js b/tests/baselines/reference/classDeclarationMergedInModuleWithContinuation.js
index 5a5440a92b5..254ac374816 100644
--- a/tests/baselines/reference/classDeclarationMergedInModuleWithContinuation.js
+++ b/tests/baselines/reference/classDeclarationMergedInModuleWithContinuation.js
@@ -33,7 +33,7 @@ var M;
     var O = (function (_super) {
         __extends(O, _super);
         function O() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return O;
     }(M.N));
diff --git a/tests/baselines/reference/classDeclaredBeforeClassFactory.js b/tests/baselines/reference/classDeclaredBeforeClassFactory.js
index 3dd1e7a4aaf..648c7709720 100644
--- a/tests/baselines/reference/classDeclaredBeforeClassFactory.js
+++ b/tests/baselines/reference/classDeclaredBeforeClassFactory.js
@@ -17,7 +17,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(makeBaseClass()));
diff --git a/tests/baselines/reference/classDoesNotDependOnBaseTypes.js b/tests/baselines/reference/classDoesNotDependOnBaseTypes.js
index 076412e164d..450529a2622 100644
--- a/tests/baselines/reference/classDoesNotDependOnBaseTypes.js
+++ b/tests/baselines/reference/classDoesNotDependOnBaseTypes.js
@@ -31,7 +31,7 @@ var StringTreeCollectionBase = (function () {
 var StringTreeCollection = (function (_super) {
     __extends(StringTreeCollection, _super);
     function StringTreeCollection() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return StringTreeCollection;
 }(StringTreeCollectionBase));
diff --git a/tests/baselines/reference/classExpression2.js b/tests/baselines/reference/classExpression2.js
index 59b62c60cfe..aa226998eb3 100644
--- a/tests/baselines/reference/classExpression2.js
+++ b/tests/baselines/reference/classExpression2.js
@@ -16,7 +16,7 @@ var D = (function () {
 var v = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(D));
diff --git a/tests/baselines/reference/classExpression3.js b/tests/baselines/reference/classExpression3.js
index c0376c54c27..991592e2cf3 100644
--- a/tests/baselines/reference/classExpression3.js
+++ b/tests/baselines/reference/classExpression3.js
@@ -15,7 +15,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(class_1, _super);
     function class_1() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.c = 3;
         return _this;
     }
@@ -23,7 +23,7 @@ var C = (function (_super) {
 }((function (_super) {
     __extends(class_2, _super);
     function class_2() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.b = 2;
         return _this;
     }
diff --git a/tests/baselines/reference/classExpressionExtendingAbstractClass.js b/tests/baselines/reference/classExpressionExtendingAbstractClass.js
index 7312ab6567d..1e564b46752 100644
--- a/tests/baselines/reference/classExpressionExtendingAbstractClass.js
+++ b/tests/baselines/reference/classExpressionExtendingAbstractClass.js
@@ -22,7 +22,7 @@ var A = (function () {
 var C = (function (_super) {
     __extends(class_1, _super);
     function class_1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return class_1;
 }(A));
diff --git a/tests/baselines/reference/classExtendingBuiltinType.js b/tests/baselines/reference/classExtendingBuiltinType.js
index 4c95e3008ea..b01b646efd3 100644
--- a/tests/baselines/reference/classExtendingBuiltinType.js
+++ b/tests/baselines/reference/classExtendingBuiltinType.js
@@ -20,70 +20,70 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C1 = (function (_super) {
     __extends(C1, _super);
     function C1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C1;
 }(Object));
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(Function));
 var C3 = (function (_super) {
     __extends(C3, _super);
     function C3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C3;
 }(String));
 var C4 = (function (_super) {
     __extends(C4, _super);
     function C4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C4;
 }(Boolean));
 var C5 = (function (_super) {
     __extends(C5, _super);
     function C5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C5;
 }(Number));
 var C6 = (function (_super) {
     __extends(C6, _super);
     function C6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C6;
 }(Date));
 var C7 = (function (_super) {
     __extends(C7, _super);
     function C7() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C7;
 }(RegExp));
 var C8 = (function (_super) {
     __extends(C8, _super);
     function C8() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C8;
 }(Error));
 var C9 = (function (_super) {
     __extends(C9, _super);
     function C9() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C9;
 }(Array));
 var C10 = (function (_super) {
     __extends(C10, _super);
     function C10() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C10;
 }(Array));
diff --git a/tests/baselines/reference/classExtendingClass.js b/tests/baselines/reference/classExtendingClass.js
index 91e3752980c..8cc5efc0fa1 100644
--- a/tests/baselines/reference/classExtendingClass.js
+++ b/tests/baselines/reference/classExtendingClass.js
@@ -47,7 +47,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
@@ -66,7 +66,7 @@ var C2 = (function () {
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(C2));
diff --git a/tests/baselines/reference/classExtendingClassLikeType.js b/tests/baselines/reference/classExtendingClassLikeType.js
index bfc10c23563..2a5374f0331 100644
--- a/tests/baselines/reference/classExtendingClassLikeType.js
+++ b/tests/baselines/reference/classExtendingClassLikeType.js
@@ -68,7 +68,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var D0 = (function (_super) {
     __extends(D0, _super);
     function D0() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D0;
 }(Base));
@@ -107,7 +107,7 @@ var D3 = (function (_super) {
 var D4 = (function (_super) {
     __extends(D4, _super);
     function D4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D4;
 }(getBase()));
@@ -115,7 +115,7 @@ var D4 = (function (_super) {
 var D5 = (function (_super) {
     __extends(D5, _super);
     function D5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D5;
 }(getBadBase()));
diff --git a/tests/baselines/reference/classExtendingNonConstructor.js b/tests/baselines/reference/classExtendingNonConstructor.js
index 574d5004486..9ecfd3da7f1 100644
--- a/tests/baselines/reference/classExtendingNonConstructor.js
+++ b/tests/baselines/reference/classExtendingNonConstructor.js
@@ -27,49 +27,49 @@ function foo() {
 var C1 = (function (_super) {
     __extends(C1, _super);
     function C1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C1;
 }(undefined));
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(true));
 var C3 = (function (_super) {
     __extends(C3, _super);
     function C3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C3;
 }(false));
 var C4 = (function (_super) {
     __extends(C4, _super);
     function C4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C4;
 }(42));
 var C5 = (function (_super) {
     __extends(C5, _super);
     function C5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C5;
 }("hello"));
 var C6 = (function (_super) {
     __extends(C6, _super);
     function C6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C6;
 }(x));
 var C7 = (function (_super) {
     __extends(C7, _super);
     function C7() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C7;
 }(foo));
diff --git a/tests/baselines/reference/classExtendingNull.js b/tests/baselines/reference/classExtendingNull.js
index 8d5d73329aa..caa9ed57ba4 100644
--- a/tests/baselines/reference/classExtendingNull.js
+++ b/tests/baselines/reference/classExtendingNull.js
@@ -12,14 +12,12 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C1 = (function (_super) {
     __extends(C1, _super);
     function C1() {
-        return _super.apply(this, arguments) || this;
     }
     return C1;
 }(null));
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
     }
     return C2;
 }((null)));
diff --git a/tests/baselines/reference/classExtendingPrimitive.js b/tests/baselines/reference/classExtendingPrimitive.js
index 53cb45c2081..d8ccd189398 100644
--- a/tests/baselines/reference/classExtendingPrimitive.js
+++ b/tests/baselines/reference/classExtendingPrimitive.js
@@ -24,28 +24,28 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(number));
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(string));
 var C3 = (function (_super) {
     __extends(C3, _super);
     function C3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C3;
 }(boolean));
 var C4 = (function (_super) {
     __extends(C4, _super);
     function C4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C4;
 }(Void));
@@ -58,28 +58,27 @@ void {};
 var C5 = (function (_super) {
     __extends(C5, _super);
     function C5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C5;
 }(Null));
 var C5a = (function (_super) {
     __extends(C5a, _super);
     function C5a() {
-        return _super.apply(this, arguments) || this;
     }
     return C5a;
 }(null));
 var C6 = (function (_super) {
     __extends(C6, _super);
     function C6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C6;
 }(undefined));
 var C7 = (function (_super) {
     __extends(C7, _super);
     function C7() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C7;
 }(Undefined));
@@ -90,7 +89,7 @@ var E;
 var C8 = (function (_super) {
     __extends(C8, _super);
     function C8() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C8;
 }(E));
diff --git a/tests/baselines/reference/classExtendingPrimitive2.js b/tests/baselines/reference/classExtendingPrimitive2.js
index b32dc31a5b4..0ad4c6e945d 100644
--- a/tests/baselines/reference/classExtendingPrimitive2.js
+++ b/tests/baselines/reference/classExtendingPrimitive2.js
@@ -20,7 +20,6 @@ void {};
 var C5a = (function (_super) {
     __extends(C5a, _super);
     function C5a() {
-        return _super.apply(this, arguments) || this;
     }
     return C5a;
 }(null));
diff --git a/tests/baselines/reference/classExtendingQualifiedName.js b/tests/baselines/reference/classExtendingQualifiedName.js
index fced8c2a373..be0f4fe0714 100644
--- a/tests/baselines/reference/classExtendingQualifiedName.js
+++ b/tests/baselines/reference/classExtendingQualifiedName.js
@@ -23,7 +23,7 @@ var M;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(M.C));
diff --git a/tests/baselines/reference/classExtendingQualifiedName2.js b/tests/baselines/reference/classExtendingQualifiedName2.js
index c133ceb87dc..0b7b56e56d5 100644
--- a/tests/baselines/reference/classExtendingQualifiedName2.js
+++ b/tests/baselines/reference/classExtendingQualifiedName2.js
@@ -24,7 +24,7 @@ var M;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(M.C));
diff --git a/tests/baselines/reference/classExtendsAcrossFiles.js b/tests/baselines/reference/classExtendsAcrossFiles.js
index 5be0ab8f9c0..399dac024d6 100644
--- a/tests/baselines/reference/classExtendsAcrossFiles.js
+++ b/tests/baselines/reference/classExtendsAcrossFiles.js
@@ -37,7 +37,7 @@ exports.b = {
         var B = (function (_super) {
             __extends(B, _super);
             function B() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return B;
         }(A));
@@ -62,7 +62,7 @@ exports.a = {
         var B = (function (_super) {
             __extends(B, _super);
             function B() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return B;
         }(A));
diff --git a/tests/baselines/reference/classExtendsClauseClassMergedWithModuleNotReferingConstructor.js b/tests/baselines/reference/classExtendsClauseClassMergedWithModuleNotReferingConstructor.js
index 91f96450d87..542fdda7c8a 100644
--- a/tests/baselines/reference/classExtendsClauseClassMergedWithModuleNotReferingConstructor.js
+++ b/tests/baselines/reference/classExtendsClauseClassMergedWithModuleNotReferingConstructor.js
@@ -32,7 +32,7 @@ var Foo;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
diff --git a/tests/baselines/reference/classExtendsClauseClassNotReferringConstructor.js b/tests/baselines/reference/classExtendsClauseClassNotReferringConstructor.js
index 6c3dc789445..fdd438c3aef 100644
--- a/tests/baselines/reference/classExtendsClauseClassNotReferringConstructor.js
+++ b/tests/baselines/reference/classExtendsClauseClassNotReferringConstructor.js
@@ -23,7 +23,7 @@ var Foo;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
diff --git a/tests/baselines/reference/classExtendsEveryObjectType.js b/tests/baselines/reference/classExtendsEveryObjectType.js
index a19f5d5cdd6..3e96a872c2e 100644
--- a/tests/baselines/reference/classExtendsEveryObjectType.js
+++ b/tests/baselines/reference/classExtendsEveryObjectType.js
@@ -25,14 +25,14 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(I)); // error
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }({ foo: string })); // error
@@ -40,7 +40,7 @@ var x;
 var C3 = (function (_super) {
     __extends(C3, _super);
     function C3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C3;
 }(x)); // error
@@ -51,7 +51,7 @@ var M;
 var C4 = (function (_super) {
     __extends(C4, _super);
     function C4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C4;
 }(M)); // error
@@ -59,14 +59,14 @@ function foo() { }
 var C5 = (function (_super) {
     __extends(C5, _super);
     function C5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C5;
 }(foo)); // error
 var C6 = (function (_super) {
     __extends(C6, _super);
     function C6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C6;
 }([])); // error
diff --git a/tests/baselines/reference/classExtendsEveryObjectType2.js b/tests/baselines/reference/classExtendsEveryObjectType2.js
index fbc364ca5da..ca3e2cff209 100644
--- a/tests/baselines/reference/classExtendsEveryObjectType2.js
+++ b/tests/baselines/reference/classExtendsEveryObjectType2.js
@@ -12,14 +12,14 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }({ foo: string })); // error
 var C6 = (function (_super) {
     __extends(C6, _super);
     function C6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C6;
 }([])); // error
diff --git a/tests/baselines/reference/classExtendsInterface.js b/tests/baselines/reference/classExtendsInterface.js
index b5946224317..4d4936330bf 100644
--- a/tests/baselines/reference/classExtendsInterface.js
+++ b/tests/baselines/reference/classExtendsInterface.js
@@ -17,7 +17,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var A = (function (_super) {
     __extends(A, _super);
     function A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A;
 }(Comparable));
@@ -29,7 +29,7 @@ var B = (function () {
 var A2 = (function (_super) {
     __extends(A2, _super);
     function A2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A2;
 }(Comparable2));
diff --git a/tests/baselines/reference/classExtendsInterfaceInExpression.js b/tests/baselines/reference/classExtendsInterfaceInExpression.js
index 9dcd8dd7279..10a17c8154c 100644
--- a/tests/baselines/reference/classExtendsInterfaceInExpression.js
+++ b/tests/baselines/reference/classExtendsInterfaceInExpression.js
@@ -20,7 +20,7 @@ function factory(a) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(factory(A)));
diff --git a/tests/baselines/reference/classExtendsInterfaceInModule.js b/tests/baselines/reference/classExtendsInterfaceInModule.js
index 9da8831a138..d7eefb3c7ed 100644
--- a/tests/baselines/reference/classExtendsInterfaceInModule.js
+++ b/tests/baselines/reference/classExtendsInterfaceInModule.js
@@ -24,21 +24,21 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C1 = (function (_super) {
     __extends(C1, _super);
     function C1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C1;
 }(M.I1));
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(M.I2));
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(Mod.Nested.I));
diff --git a/tests/baselines/reference/classExtendsItself.js b/tests/baselines/reference/classExtendsItself.js
index 36f2263d671..d8dfea40fa9 100644
--- a/tests/baselines/reference/classExtendsItself.js
+++ b/tests/baselines/reference/classExtendsItself.js
@@ -14,21 +14,21 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(C)); // error
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(D)); // error
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E;
 }(E)); // error
diff --git a/tests/baselines/reference/classExtendsItselfIndirectly.js b/tests/baselines/reference/classExtendsItselfIndirectly.js
index 0f3f48d2f2c..7ee58914d93 100644
--- a/tests/baselines/reference/classExtendsItselfIndirectly.js
+++ b/tests/baselines/reference/classExtendsItselfIndirectly.js
@@ -20,42 +20,42 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(E)); // error
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E;
 }(D));
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(E2)); // error
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(C2));
 var E2 = (function (_super) {
     __extends(E2, _super);
     function E2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E2;
 }(D2));
diff --git a/tests/baselines/reference/classExtendsItselfIndirectly2.js b/tests/baselines/reference/classExtendsItselfIndirectly2.js
index e215a07c357..6db36996c56 100644
--- a/tests/baselines/reference/classExtendsItselfIndirectly2.js
+++ b/tests/baselines/reference/classExtendsItselfIndirectly2.js
@@ -31,7 +31,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(N.E)); // error
@@ -40,7 +40,7 @@ var M;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(C));
@@ -51,7 +51,7 @@ var N;
     var E = (function (_super) {
         __extends(E, _super);
         function E() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return E;
     }(M.D));
@@ -62,7 +62,7 @@ var O;
     var C2 = (function (_super) {
         __extends(C2, _super);
         function C2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return C2;
     }(Q.E2)); // error
@@ -71,7 +71,7 @@ var O;
         var D2 = (function (_super) {
             __extends(D2, _super);
             function D2() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return D2;
         }(C2));
@@ -82,7 +82,7 @@ var O;
         var E2 = (function (_super) {
             __extends(E2, _super);
             function E2() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return E2;
         }(P.D2));
diff --git a/tests/baselines/reference/classExtendsItselfIndirectly3.js b/tests/baselines/reference/classExtendsItselfIndirectly3.js
index f8366d77e13..866f0a592aa 100644
--- a/tests/baselines/reference/classExtendsItselfIndirectly3.js
+++ b/tests/baselines/reference/classExtendsItselfIndirectly3.js
@@ -27,7 +27,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(E)); // error
@@ -40,7 +40,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
@@ -53,7 +53,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E;
 }(D));
@@ -66,7 +66,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(E2)); // error
@@ -79,7 +79,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(C2));
@@ -92,7 +92,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var E2 = (function (_super) {
     __extends(E2, _super);
     function E2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E2;
 }(D2));
diff --git a/tests/baselines/reference/classExtendsMultipleBaseClasses.js b/tests/baselines/reference/classExtendsMultipleBaseClasses.js
index cd9c28ad283..7adb3af9b6f 100644
--- a/tests/baselines/reference/classExtendsMultipleBaseClasses.js
+++ b/tests/baselines/reference/classExtendsMultipleBaseClasses.js
@@ -22,7 +22,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/classExtendsNull.js b/tests/baselines/reference/classExtendsNull.js
index 1eeb5172cad..37fcb0c6b2e 100644
--- a/tests/baselines/reference/classExtendsNull.js
+++ b/tests/baselines/reference/classExtendsNull.js
@@ -21,7 +21,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        var _this = _super.call(this) || this;
+        _this = _super.call(this) || this;
         return Object.create(null);
     }
     return C;
@@ -29,7 +29,6 @@ var C = (function (_super) {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
         return Object.create(null);
     }
     return D;
diff --git a/tests/baselines/reference/classExtendsShadowedConstructorFunction.js b/tests/baselines/reference/classExtendsShadowedConstructorFunction.js
index ddaadc2dc62..7d5790a8067 100644
--- a/tests/baselines/reference/classExtendsShadowedConstructorFunction.js
+++ b/tests/baselines/reference/classExtendsShadowedConstructorFunction.js
@@ -25,7 +25,7 @@ var M;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(C));
diff --git a/tests/baselines/reference/classExtendsValidConstructorFunction.js b/tests/baselines/reference/classExtendsValidConstructorFunction.js
index 31bff6e430c..b97c57a9a57 100644
--- a/tests/baselines/reference/classExtendsValidConstructorFunction.js
+++ b/tests/baselines/reference/classExtendsValidConstructorFunction.js
@@ -16,7 +16,7 @@ var x = new foo(); // can be used as a constructor function
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(foo)); // error, cannot extend it though
diff --git a/tests/baselines/reference/classHeritageWithTrailingSeparator.js b/tests/baselines/reference/classHeritageWithTrailingSeparator.js
index 12265f569bd..7102a96cdaf 100644
--- a/tests/baselines/reference/classHeritageWithTrailingSeparator.js
+++ b/tests/baselines/reference/classHeritageWithTrailingSeparator.js
@@ -17,7 +17,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/classImplementsClass2.js b/tests/baselines/reference/classImplementsClass2.js
index 5e3eae46543..5994e07d528 100644
--- a/tests/baselines/reference/classImplementsClass2.js
+++ b/tests/baselines/reference/classImplementsClass2.js
@@ -33,7 +33,7 @@ var C = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C2.prototype.foo = function () {
         return 1;
diff --git a/tests/baselines/reference/classImplementsClass3.js b/tests/baselines/reference/classImplementsClass3.js
index 5fd003e93b9..440bedc3962 100644
--- a/tests/baselines/reference/classImplementsClass3.js
+++ b/tests/baselines/reference/classImplementsClass3.js
@@ -37,7 +37,7 @@ var C = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(A));
diff --git a/tests/baselines/reference/classImplementsClass4.js b/tests/baselines/reference/classImplementsClass4.js
index 477288972df..98f7849d5bb 100644
--- a/tests/baselines/reference/classImplementsClass4.js
+++ b/tests/baselines/reference/classImplementsClass4.js
@@ -40,7 +40,7 @@ var C = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(A));
diff --git a/tests/baselines/reference/classImplementsClass5.js b/tests/baselines/reference/classImplementsClass5.js
index 0ec258ab77b..aefec9ee4c5 100644
--- a/tests/baselines/reference/classImplementsClass5.js
+++ b/tests/baselines/reference/classImplementsClass5.js
@@ -42,7 +42,7 @@ var C = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(A));
diff --git a/tests/baselines/reference/classImplementsClass6.js b/tests/baselines/reference/classImplementsClass6.js
index 0771c56415c..dd2b4039d49 100644
--- a/tests/baselines/reference/classImplementsClass6.js
+++ b/tests/baselines/reference/classImplementsClass6.js
@@ -47,7 +47,7 @@ var C = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(A));
diff --git a/tests/baselines/reference/classIndexer3.js b/tests/baselines/reference/classIndexer3.js
index 2e55c894645..7729d2b26ec 100644
--- a/tests/baselines/reference/classIndexer3.js
+++ b/tests/baselines/reference/classIndexer3.js
@@ -24,7 +24,7 @@ var C123 = (function () {
 var D123 = (function (_super) {
     __extends(D123, _super);
     function D123() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D123;
 }(C123));
diff --git a/tests/baselines/reference/classInheritence.js b/tests/baselines/reference/classInheritence.js
index f68d76fad47..936cf0973ee 100644
--- a/tests/baselines/reference/classInheritence.js
+++ b/tests/baselines/reference/classInheritence.js
@@ -11,14 +11,14 @@ var __extends = (this && this.__extends) || function (d, b) {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var A = (function (_super) {
     __extends(A, _super);
     function A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A;
 }(A));
diff --git a/tests/baselines/reference/classIsSubtypeOfBaseType.js b/tests/baselines/reference/classIsSubtypeOfBaseType.js
index 52300987d8e..b4d730257a3 100644
--- a/tests/baselines/reference/classIsSubtypeOfBaseType.js
+++ b/tests/baselines/reference/classIsSubtypeOfBaseType.js
@@ -29,14 +29,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/classOrder2.js b/tests/baselines/reference/classOrder2.js
index 63490fa29b1..0d41a7f6e80 100644
--- a/tests/baselines/reference/classOrder2.js
+++ b/tests/baselines/reference/classOrder2.js
@@ -28,7 +28,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var A = (function (_super) {
     __extends(A, _super);
     function A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     A.prototype.foo = function () { this.bar(); };
     return A;
diff --git a/tests/baselines/reference/classOrderBug.js b/tests/baselines/reference/classOrderBug.js
index e21a5ed64cf..d1596d781cd 100644
--- a/tests/baselines/reference/classOrderBug.js
+++ b/tests/baselines/reference/classOrderBug.js
@@ -35,7 +35,7 @@ var baz = (function () {
 var foo = (function (_super) {
     __extends(foo, _super);
     function foo() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return foo;
 }(baz));
diff --git a/tests/baselines/reference/classSideInheritance1.js b/tests/baselines/reference/classSideInheritance1.js
index 9443509032c..f1ec0e4d6f6 100644
--- a/tests/baselines/reference/classSideInheritance1.js
+++ b/tests/baselines/reference/classSideInheritance1.js
@@ -33,7 +33,7 @@ var A = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(A));
diff --git a/tests/baselines/reference/classUpdateTests.js b/tests/baselines/reference/classUpdateTests.js
index 53ef71d0e4b..3859cc297d2 100644
--- a/tests/baselines/reference/classUpdateTests.js
+++ b/tests/baselines/reference/classUpdateTests.js
@@ -157,7 +157,7 @@ var D = (function () {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.p1 = 0;
         return _this;
     }
@@ -166,7 +166,7 @@ var E = (function (_super) {
 var F = (function (_super) {
     __extends(F, _super);
     function F() {
-        var _this;
+        var _this = this;
         return _this;
     } // ERROR - super call required
     return F;
@@ -205,7 +205,7 @@ var J = (function (_super) {
 var K = (function (_super) {
     __extends(K, _super);
     function K(p1) {
-        var _this;
+        var _this = this;
         _this.p1 = p1;
         var i = 0;
         _this = _super.call(this) || this;
@@ -225,7 +225,7 @@ var L = (function (_super) {
 var M = (function (_super) {
     __extends(M, _super);
     function M(p1) {
-        var _this;
+        var _this = this;
         _this.p1 = p1;
         var i = 0;
         _this = _super.call(this) || this;
diff --git a/tests/baselines/reference/classWithBaseClassButNoConstructor.js b/tests/baselines/reference/classWithBaseClassButNoConstructor.js
index c25687d3c74..70a495d6dd1 100644
--- a/tests/baselines/reference/classWithBaseClassButNoConstructor.js
+++ b/tests/baselines/reference/classWithBaseClassButNoConstructor.js
@@ -54,7 +54,7 @@ var Base = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(Base));
@@ -69,7 +69,7 @@ var Base2 = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(Base2));
@@ -80,7 +80,7 @@ var d2 = new D(1); // ok
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(Base2));
@@ -90,7 +90,7 @@ var d4 = new D(1); // ok
 var D3 = (function (_super) {
     __extends(D3, _super);
     function D3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D3;
 }(Base2));
diff --git a/tests/baselines/reference/classWithConstructors.js b/tests/baselines/reference/classWithConstructors.js
index f445d22d18f..482512c1e4a 100644
--- a/tests/baselines/reference/classWithConstructors.js
+++ b/tests/baselines/reference/classWithConstructors.js
@@ -75,7 +75,7 @@ var NonGeneric;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(C2));
@@ -103,7 +103,7 @@ var Generics;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(C2));
diff --git a/tests/baselines/reference/classWithProtectedProperty.js b/tests/baselines/reference/classWithProtectedProperty.js
index 2cb8a4e0a50..f90c98f8699 100644
--- a/tests/baselines/reference/classWithProtectedProperty.js
+++ b/tests/baselines/reference/classWithProtectedProperty.js
@@ -48,7 +48,7 @@ C.g = function () { return ''; };
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.method = function () {
         // No errors
diff --git a/tests/baselines/reference/classWithStaticMembers.js b/tests/baselines/reference/classWithStaticMembers.js
index 9e79780d5cc..af4e448d09b 100644
--- a/tests/baselines/reference/classWithStaticMembers.js
+++ b/tests/baselines/reference/classWithStaticMembers.js
@@ -45,7 +45,7 @@ var r3 = r.foo;
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/classdecl.js b/tests/baselines/reference/classdecl.js
index a3059757d2f..5f40a3de86e 100644
--- a/tests/baselines/reference/classdecl.js
+++ b/tests/baselines/reference/classdecl.js
@@ -136,7 +136,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
@@ -161,7 +161,7 @@ var m2;
         var c = (function (_super) {
             __extends(c, _super);
             function c() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return c;
         }(b));
@@ -177,7 +177,7 @@ var m2;
 var c = (function (_super) {
     __extends(c, _super);
     function c() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return c;
 }(m1.b));
diff --git a/tests/baselines/reference/clodulesDerivedClasses.js b/tests/baselines/reference/clodulesDerivedClasses.js
index ea4bfcf301f..ab63e27b00b 100644
--- a/tests/baselines/reference/clodulesDerivedClasses.js
+++ b/tests/baselines/reference/clodulesDerivedClasses.js
@@ -43,7 +43,7 @@ var Shape = (function () {
 var Path = (function (_super) {
     __extends(Path, _super);
     function Path() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Path;
 }(Shape));
diff --git a/tests/baselines/reference/collisionSuperAndLocalFunctionInAccessors.js b/tests/baselines/reference/collisionSuperAndLocalFunctionInAccessors.js
index 85c0e398fbd..964d5826773 100644
--- a/tests/baselines/reference/collisionSuperAndLocalFunctionInAccessors.js
+++ b/tests/baselines/reference/collisionSuperAndLocalFunctionInAccessors.js
@@ -68,7 +68,7 @@ var Foo = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(b.prototype, "prop2", {
         get: function () {
@@ -88,7 +88,7 @@ var b = (function (_super) {
 var c = (function (_super) {
     __extends(c, _super);
     function c() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(c.prototype, "prop2", {
         get: function () {
diff --git a/tests/baselines/reference/collisionSuperAndLocalFunctionInMethod.js b/tests/baselines/reference/collisionSuperAndLocalFunctionInMethod.js
index 81c069da169..1fce1338fe7 100644
--- a/tests/baselines/reference/collisionSuperAndLocalFunctionInMethod.js
+++ b/tests/baselines/reference/collisionSuperAndLocalFunctionInMethod.js
@@ -50,7 +50,7 @@ var Foo = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.prototype.foo = function () {
         function _super() {
@@ -63,7 +63,7 @@ var b = (function (_super) {
 var c = (function (_super) {
     __extends(c, _super);
     function c() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     c.prototype.foo = function () {
         var x = function () {
diff --git a/tests/baselines/reference/collisionSuperAndLocalFunctionInProperty.js b/tests/baselines/reference/collisionSuperAndLocalFunctionInProperty.js
index 67b7f0e3991..a251c62a161 100644
--- a/tests/baselines/reference/collisionSuperAndLocalFunctionInProperty.js
+++ b/tests/baselines/reference/collisionSuperAndLocalFunctionInProperty.js
@@ -40,7 +40,7 @@ var Foo = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.prop2 = {
             doStuff: function () {
                 function _super() {
diff --git a/tests/baselines/reference/collisionSuperAndLocalVarInAccessors.js b/tests/baselines/reference/collisionSuperAndLocalVarInAccessors.js
index 26f782c0d17..0b89b219338 100644
--- a/tests/baselines/reference/collisionSuperAndLocalVarInAccessors.js
+++ b/tests/baselines/reference/collisionSuperAndLocalVarInAccessors.js
@@ -58,7 +58,7 @@ var Foo = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(b.prototype, "prop2", {
         get: function () {
@@ -76,7 +76,7 @@ var b = (function (_super) {
 var c = (function (_super) {
     __extends(c, _super);
     function c() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(c.prototype, "prop2", {
         get: function () {
diff --git a/tests/baselines/reference/collisionSuperAndLocalVarInMethod.js b/tests/baselines/reference/collisionSuperAndLocalVarInMethod.js
index 0524d993ba1..888677ca422 100644
--- a/tests/baselines/reference/collisionSuperAndLocalVarInMethod.js
+++ b/tests/baselines/reference/collisionSuperAndLocalVarInMethod.js
@@ -36,7 +36,7 @@ var Foo = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.prototype.foo = function () {
         var _super = 10; // Should be error 
@@ -46,7 +46,7 @@ var b = (function (_super) {
 var c = (function (_super) {
     __extends(c, _super);
     function c() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     c.prototype.foo = function () {
         var x = function () {
diff --git a/tests/baselines/reference/collisionSuperAndLocalVarInProperty.js b/tests/baselines/reference/collisionSuperAndLocalVarInProperty.js
index d793e022c6b..aabc083deda 100644
--- a/tests/baselines/reference/collisionSuperAndLocalVarInProperty.js
+++ b/tests/baselines/reference/collisionSuperAndLocalVarInProperty.js
@@ -38,7 +38,7 @@ var Foo = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.prop2 = {
             doStuff: function () {
                 var _super = 10; // Should be error 
diff --git a/tests/baselines/reference/collisionSuperAndNameResolution.js b/tests/baselines/reference/collisionSuperAndNameResolution.js
index cb5636ec904..a6a36efcd1f 100644
--- a/tests/baselines/reference/collisionSuperAndNameResolution.js
+++ b/tests/baselines/reference/collisionSuperAndNameResolution.js
@@ -27,7 +27,7 @@ var base = (function () {
 var Foo = (function (_super) {
     __extends(Foo, _super);
     function Foo() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Foo.prototype.x = function () {
         console.log(_super); // Error as this doesnt not resolve to user defined _super
diff --git a/tests/baselines/reference/collisionSuperAndParameter1.js b/tests/baselines/reference/collisionSuperAndParameter1.js
index ed19500f9d4..5ede279d859 100644
--- a/tests/baselines/reference/collisionSuperAndParameter1.js
+++ b/tests/baselines/reference/collisionSuperAndParameter1.js
@@ -23,7 +23,7 @@ var Foo = (function () {
 var Foo2 = (function (_super) {
     __extends(Foo2, _super);
     function Foo2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Foo2.prototype.x = function () {
         var lambda = function (_super) {
diff --git a/tests/baselines/reference/collisionThisExpressionAndLocalVarWithSuperExperssion.js b/tests/baselines/reference/collisionThisExpressionAndLocalVarWithSuperExperssion.js
index 9e8132c6883..9cd524ef8b8 100644
--- a/tests/baselines/reference/collisionThisExpressionAndLocalVarWithSuperExperssion.js
+++ b/tests/baselines/reference/collisionThisExpressionAndLocalVarWithSuperExperssion.js
@@ -34,7 +34,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.prototype.foo = function () {
         var _this = this;
@@ -46,7 +46,7 @@ var b = (function (_super) {
 var b2 = (function (_super) {
     __extends(b2, _super);
     function b2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b2.prototype.foo = function () {
         var _this = this;
diff --git a/tests/baselines/reference/commentsInheritance.js b/tests/baselines/reference/commentsInheritance.js
index 3527f5d23bb..aa7b7910b02 100644
--- a/tests/baselines/reference/commentsInheritance.js
+++ b/tests/baselines/reference/commentsInheritance.js
@@ -258,7 +258,7 @@ c2_i = c3_i;
 var c4 = (function (_super) {
     __extends(c4, _super);
     function c4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return c4;
 }(c2));
diff --git a/tests/baselines/reference/comparisonOperatorWithIdenticalObjects.js b/tests/baselines/reference/comparisonOperatorWithIdenticalObjects.js
index a263a30e382..82c9d1b65f7 100644
--- a/tests/baselines/reference/comparisonOperatorWithIdenticalObjects.js
+++ b/tests/baselines/reference/comparisonOperatorWithIdenticalObjects.js
@@ -227,14 +227,14 @@ var Base = (function () {
 var A2 = (function (_super) {
     __extends(A2, _super);
     function A2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A2;
 }(Base));
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnCallSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnCallSignature.js
index b8584522b7b..a18b5d19ebd 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnCallSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnCallSignature.js
@@ -182,7 +182,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnConstructorSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnConstructorSignature.js
index 93e1e876a7f..5498a006e0c 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnConstructorSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnConstructorSignature.js
@@ -182,7 +182,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnIndexSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnIndexSignature.js
index a8973bf2c10..431c19c0bbe 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnIndexSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnIndexSignature.js
@@ -125,7 +125,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedCallSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedCallSignature.js
index 4539538782d..6669d835c10 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedCallSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedCallSignature.js
@@ -163,7 +163,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedConstructorSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedConstructorSignature.js
index 5e8412bc361..0d047de4f9f 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedConstructorSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedConstructorSignature.js
@@ -163,7 +163,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnCallSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnCallSignature.js
index d30c3586b12..0f32da7d9de 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnCallSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnCallSignature.js
@@ -273,7 +273,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnConstructorSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnConstructorSignature.js
index 4235c1352d4..a5e64b0060a 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnConstructorSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnConstructorSignature.js
@@ -235,7 +235,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnIndexSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnIndexSignature.js
index 9a6fecd668d..aad6778162f 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnIndexSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnIndexSignature.js
@@ -121,7 +121,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedCallSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedCallSignature.js
index 5721a452486..70340933d15 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedCallSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedCallSignature.js
@@ -178,7 +178,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedConstructorSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedConstructorSignature.js
index b6bf8a16e61..fa0f07f986f 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedConstructorSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedConstructorSignature.js
@@ -178,7 +178,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnProperty.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnProperty.js
index 690214fc00f..0db97fed414 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnProperty.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnProperty.js
@@ -92,7 +92,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -114,7 +114,7 @@ var A2 = (function () {
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A2));
diff --git a/tests/baselines/reference/complexClassRelationships.js b/tests/baselines/reference/complexClassRelationships.js
index 4f48e5fc2c5..99a04a07e53 100644
--- a/tests/baselines/reference/complexClassRelationships.js
+++ b/tests/baselines/reference/complexClassRelationships.js
@@ -57,7 +57,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.createEmpty = function () {
         var item = new Derived();
diff --git a/tests/baselines/reference/complicatedGenericRecursiveBaseClassReference.js b/tests/baselines/reference/complicatedGenericRecursiveBaseClassReference.js
index 326c0830c4f..15b26480898 100644
--- a/tests/baselines/reference/complicatedGenericRecursiveBaseClassReference.js
+++ b/tests/baselines/reference/complicatedGenericRecursiveBaseClassReference.js
@@ -14,7 +14,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var S18 = (function (_super) {
     __extends(S18, _super);
     function S18() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return S18;
 }(S18));
diff --git a/tests/baselines/reference/computedPropertyNames24_ES5.js b/tests/baselines/reference/computedPropertyNames24_ES5.js
index ff9112755bd..6b8947f857f 100644
--- a/tests/baselines/reference/computedPropertyNames24_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames24_ES5.js
@@ -25,7 +25,7 @@ var Base = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype[_super.bar.call(this)] = function () { };
     return C;
diff --git a/tests/baselines/reference/computedPropertyNames25_ES5.js b/tests/baselines/reference/computedPropertyNames25_ES5.js
index dad9c5c291a..f2085c1b4a8 100644
--- a/tests/baselines/reference/computedPropertyNames25_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames25_ES5.js
@@ -30,7 +30,7 @@ var Base = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.foo = function () {
         var obj = (_a = {},
diff --git a/tests/baselines/reference/computedPropertyNames26_ES5.js b/tests/baselines/reference/computedPropertyNames26_ES5.js
index 5db7768270a..accb2b74e98 100644
--- a/tests/baselines/reference/computedPropertyNames26_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames26_ES5.js
@@ -27,7 +27,7 @@ var Base = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype[(_a = {}, _a[_super.bar.call(this)] = 1, _a)[0]] = function () { };
     return C;
diff --git a/tests/baselines/reference/computedPropertyNames27_ES5.js b/tests/baselines/reference/computedPropertyNames27_ES5.js
index 381805659e2..742baeab1ef 100644
--- a/tests/baselines/reference/computedPropertyNames27_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames27_ES5.js
@@ -19,7 +19,7 @@ var Base = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype[(_this = _super.call(this) || this, "prop")] = function () { };
     return C;
diff --git a/tests/baselines/reference/computedPropertyNames31_ES5.js b/tests/baselines/reference/computedPropertyNames31_ES5.js
index 00cc765f4cc..e084849a509 100644
--- a/tests/baselines/reference/computedPropertyNames31_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames31_ES5.js
@@ -32,7 +32,7 @@ var Base = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.foo = function () {
         var _this = this;
diff --git a/tests/baselines/reference/computedPropertyNames43_ES5.js b/tests/baselines/reference/computedPropertyNames43_ES5.js
index b1bb0fec72c..2be00852432 100644
--- a/tests/baselines/reference/computedPropertyNames43_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames43_ES5.js
@@ -36,7 +36,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(D.prototype, "get1", {
         // Computed properties
diff --git a/tests/baselines/reference/computedPropertyNames44_ES5.js b/tests/baselines/reference/computedPropertyNames44_ES5.js
index bf940f15014..87139b16220 100644
--- a/tests/baselines/reference/computedPropertyNames44_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames44_ES5.js
@@ -40,7 +40,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(D.prototype, "set1", {
         set: function (p) { },
diff --git a/tests/baselines/reference/computedPropertyNames45_ES5.js b/tests/baselines/reference/computedPropertyNames45_ES5.js
index 5b5d64f9bf0..7faaa5dd40e 100644
--- a/tests/baselines/reference/computedPropertyNames45_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames45_ES5.js
@@ -41,7 +41,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(D.prototype, "set1", {
         set: function (p) { },
diff --git a/tests/baselines/reference/conditionalOperatorWithIdenticalBCT.js b/tests/baselines/reference/conditionalOperatorWithIdenticalBCT.js
index 408571af42a..93f8f05e672 100644
--- a/tests/baselines/reference/conditionalOperatorWithIdenticalBCT.js
+++ b/tests/baselines/reference/conditionalOperatorWithIdenticalBCT.js
@@ -63,7 +63,7 @@ var X = (function () {
 var A = (function (_super) {
     __extends(A, _super);
     function A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A;
 }(X));
@@ -71,7 +71,7 @@ var A = (function (_super) {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(X));
diff --git a/tests/baselines/reference/conditionalOperatorWithoutIdenticalBCT.js b/tests/baselines/reference/conditionalOperatorWithoutIdenticalBCT.js
index 0ac935a582a..6dbcdf4842f 100644
--- a/tests/baselines/reference/conditionalOperatorWithoutIdenticalBCT.js
+++ b/tests/baselines/reference/conditionalOperatorWithoutIdenticalBCT.js
@@ -39,7 +39,7 @@ var X = (function () {
 var A = (function (_super) {
     __extends(A, _super);
     function A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A;
 }(X));
@@ -47,7 +47,7 @@ var A = (function (_super) {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(X));
diff --git a/tests/baselines/reference/constantOverloadFunction.js b/tests/baselines/reference/constantOverloadFunction.js
index 160191c5ca0..e222a7a9d6f 100644
--- a/tests/baselines/reference/constantOverloadFunction.js
+++ b/tests/baselines/reference/constantOverloadFunction.js
@@ -28,7 +28,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.prototype.bar = function () { };
     return Derived1;
@@ -36,7 +36,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived2.prototype.baz = function () { };
     return Derived2;
@@ -44,7 +44,7 @@ var Derived2 = (function (_super) {
 var Derived3 = (function (_super) {
     __extends(Derived3, _super);
     function Derived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived3.prototype.biz = function () { };
     return Derived3;
diff --git a/tests/baselines/reference/constantOverloadFunctionNoSubtypeError.js b/tests/baselines/reference/constantOverloadFunctionNoSubtypeError.js
index 509f9ba70e6..b92f23db351 100644
--- a/tests/baselines/reference/constantOverloadFunctionNoSubtypeError.js
+++ b/tests/baselines/reference/constantOverloadFunctionNoSubtypeError.js
@@ -29,7 +29,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.prototype.bar = function () { };
     return Derived1;
@@ -37,7 +37,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived2.prototype.baz = function () { };
     return Derived2;
@@ -45,7 +45,7 @@ var Derived2 = (function (_super) {
 var Derived3 = (function (_super) {
     __extends(Derived3, _super);
     function Derived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived3.prototype.biz = function () { };
     return Derived3;
diff --git a/tests/baselines/reference/constraintCheckInGenericBaseTypeReference.js b/tests/baselines/reference/constraintCheckInGenericBaseTypeReference.js
index 7908d36a56a..c574c483038 100644
--- a/tests/baselines/reference/constraintCheckInGenericBaseTypeReference.js
+++ b/tests/baselines/reference/constraintCheckInGenericBaseTypeReference.js
@@ -40,7 +40,7 @@ var GenericBase = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(GenericBase));
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance2.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance2.js
index 6b308d88896..0039746bf94 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance2.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance2.js
@@ -84,21 +84,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance3.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance3.js
index 09abd6e0868..6d715ec31d1 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance3.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance3.js
@@ -129,21 +129,21 @@ var Errors;
     var Derived = (function (_super) {
         __extends(Derived, _super);
         function Derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived;
     }(Base));
     var Derived2 = (function (_super) {
         __extends(Derived2, _super);
         function Derived2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived2;
     }(Derived));
     var OtherDerived = (function (_super) {
         __extends(OtherDerived, _super);
         function OtherDerived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return OtherDerived;
     }(Base));
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance4.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance4.js
index 4e9a8c59bf9..c6f9812e5c0 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance4.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance4.js
@@ -74,21 +74,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance5.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance5.js
index 91ec3b313bb..ee94926864e 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance5.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance5.js
@@ -64,21 +64,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance6.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance6.js
index edafb009916..017984442e4 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance6.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance6.js
@@ -67,21 +67,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType.js b/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType.js
index 45ed976e191..cf8b9b3274f 100644
--- a/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType.js
+++ b/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType.js
@@ -33,14 +33,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/constructorHasPrototypeProperty.js b/tests/baselines/reference/constructorHasPrototypeProperty.js
index a16694cdbf5..0e9ab1c59df 100644
--- a/tests/baselines/reference/constructorHasPrototypeProperty.js
+++ b/tests/baselines/reference/constructorHasPrototypeProperty.js
@@ -47,7 +47,7 @@ var NonGeneric;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(C));
@@ -66,7 +66,7 @@ var Generic;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(C));
diff --git a/tests/baselines/reference/constructorOverloads3.js b/tests/baselines/reference/constructorOverloads3.js
index c0ae9b452f9..4afc4e72272 100644
--- a/tests/baselines/reference/constructorOverloads3.js
+++ b/tests/baselines/reference/constructorOverloads3.js
@@ -31,7 +31,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var Foo = (function (_super) {
     __extends(Foo, _super);
     function Foo(x, y) {
-        var _this;
+        var _this = this;
         return _this;
     }
     Foo.prototype.bar1 = function () { };
diff --git a/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.js b/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.js
index d4cd737ab46..e3d106a2b1e 100644
--- a/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.js
+++ b/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.js
@@ -525,7 +525,7 @@ method2();
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.method2 = function () {
         return this.method1(2);
diff --git a/tests/baselines/reference/contextualTypingArrayOfLambdas.js b/tests/baselines/reference/contextualTypingArrayOfLambdas.js
index caf7ed445e5..d2d5ce60ede 100644
--- a/tests/baselines/reference/contextualTypingArrayOfLambdas.js
+++ b/tests/baselines/reference/contextualTypingArrayOfLambdas.js
@@ -28,14 +28,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/contextualTypingOfConditionalExpression.js b/tests/baselines/reference/contextualTypingOfConditionalExpression.js
index a6ce98f61e2..a7c19749b09 100644
--- a/tests/baselines/reference/contextualTypingOfConditionalExpression.js
+++ b/tests/baselines/reference/contextualTypingOfConditionalExpression.js
@@ -29,14 +29,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/contextualTypingOfConditionalExpression2.js b/tests/baselines/reference/contextualTypingOfConditionalExpression2.js
index e3bd1643cfb..d17e5b40f6e 100644
--- a/tests/baselines/reference/contextualTypingOfConditionalExpression2.js
+++ b/tests/baselines/reference/contextualTypingOfConditionalExpression2.js
@@ -26,14 +26,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/crashInsourcePropertyIsRelatableToTargetProperty.js b/tests/baselines/reference/crashInsourcePropertyIsRelatableToTargetProperty.js
index 89979da4812..36fbbe7272e 100644
--- a/tests/baselines/reference/crashInsourcePropertyIsRelatableToTargetProperty.js
+++ b/tests/baselines/reference/crashInsourcePropertyIsRelatableToTargetProperty.js
@@ -25,7 +25,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/declFileClassExtendsNull.js b/tests/baselines/reference/declFileClassExtendsNull.js
index 30ddc3f08bf..4ba73ff5067 100644
--- a/tests/baselines/reference/declFileClassExtendsNull.js
+++ b/tests/baselines/reference/declFileClassExtendsNull.js
@@ -12,7 +12,6 @@ var __extends = (this && this.__extends) || function (d, b) {
 var ExtendsNull = (function (_super) {
     __extends(ExtendsNull, _super);
     function ExtendsNull() {
-        return _super.apply(this, arguments) || this;
     }
     return ExtendsNull;
 }(null));
diff --git a/tests/baselines/reference/declFileForFunctionTypeAsTypeParameter.js b/tests/baselines/reference/declFileForFunctionTypeAsTypeParameter.js
index 442007d9b9a..50b05111e90 100644
--- a/tests/baselines/reference/declFileForFunctionTypeAsTypeParameter.js
+++ b/tests/baselines/reference/declFileForFunctionTypeAsTypeParameter.js
@@ -23,7 +23,7 @@ var X = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(X));
diff --git a/tests/baselines/reference/declFileGenericClassWithGenericExtendedClass.js b/tests/baselines/reference/declFileGenericClassWithGenericExtendedClass.js
index 47593dc9d68..ac62f03c4bf 100644
--- a/tests/baselines/reference/declFileGenericClassWithGenericExtendedClass.js
+++ b/tests/baselines/reference/declFileGenericClassWithGenericExtendedClass.js
@@ -26,7 +26,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/declFileGenericType.js b/tests/baselines/reference/declFileGenericType.js
index b2e99a73ad7..ecb37be15b0 100644
--- a/tests/baselines/reference/declFileGenericType.js
+++ b/tests/baselines/reference/declFileGenericType.js
@@ -91,7 +91,7 @@ exports.g = C.F5();
 var h = (function (_super) {
     __extends(h, _super);
     function h() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return h;
 }(C.A));
diff --git a/tests/baselines/reference/declFileWithClassNameConflictingWithClassReferredByExtendsClause.js b/tests/baselines/reference/declFileWithClassNameConflictingWithClassReferredByExtendsClause.js
index 17d885788dd..387a3fc2cb3 100644
--- a/tests/baselines/reference/declFileWithClassNameConflictingWithClassReferredByExtendsClause.js
+++ b/tests/baselines/reference/declFileWithClassNameConflictingWithClassReferredByExtendsClause.js
@@ -35,7 +35,7 @@ var X;
             var W = (function (_super) {
                 __extends(W, _super);
                 function W() {
-                    return _super.apply(this, arguments) || this;
+                    return _super !== null && _super.apply(this, arguments) || this;
                 }
                 return W;
             }(A.B.Base.W));
@@ -53,7 +53,7 @@ var X;
                 var W = (function (_super) {
                     __extends(W, _super);
                     function W() {
-                        return _super.apply(this, arguments) || this;
+                        return _super !== null && _super.apply(this, arguments) || this;
                     }
                     return W;
                 }(X.Y.base.W));
diff --git a/tests/baselines/reference/declFileWithExtendsClauseThatHasItsContainerNameConflict.js b/tests/baselines/reference/declFileWithExtendsClauseThatHasItsContainerNameConflict.js
index 70d0cd5a3dd..1efbff93dbf 100644
--- a/tests/baselines/reference/declFileWithExtendsClauseThatHasItsContainerNameConflict.js
+++ b/tests/baselines/reference/declFileWithExtendsClauseThatHasItsContainerNameConflict.js
@@ -44,7 +44,7 @@ var A;
             var ContextMenu = (function (_super) {
                 __extends(ContextMenu, _super);
                 function ContextMenu() {
-                    return _super.apply(this, arguments) || this;
+                    return _super !== null && _super.apply(this, arguments) || this;
                 }
                 return ContextMenu;
             }(B.EventManager));
diff --git a/tests/baselines/reference/declarationEmitExpressionInExtends.js b/tests/baselines/reference/declarationEmitExpressionInExtends.js
index 726c7b22446..681d827b9f6 100644
--- a/tests/baselines/reference/declarationEmitExpressionInExtends.js
+++ b/tests/baselines/reference/declarationEmitExpressionInExtends.js
@@ -29,7 +29,7 @@ var Q = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(x));
diff --git a/tests/baselines/reference/declarationEmitExpressionInExtends2.js b/tests/baselines/reference/declarationEmitExpressionInExtends2.js
index 4081de6d3ed..836ac8a47b0 100644
--- a/tests/baselines/reference/declarationEmitExpressionInExtends2.js
+++ b/tests/baselines/reference/declarationEmitExpressionInExtends2.js
@@ -29,7 +29,7 @@ function getClass(c) {
 var MyClass = (function (_super) {
     __extends(MyClass, _super);
     function MyClass() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyClass;
 }(getClass(2)));
diff --git a/tests/baselines/reference/declarationEmitExpressionInExtends3.js b/tests/baselines/reference/declarationEmitExpressionInExtends3.js
index f36a7e250a2..b7d19e94112 100644
--- a/tests/baselines/reference/declarationEmitExpressionInExtends3.js
+++ b/tests/baselines/reference/declarationEmitExpressionInExtends3.js
@@ -70,7 +70,7 @@ function getExportedClass(c) {
 var MyClass = (function (_super) {
     __extends(MyClass, _super);
     function MyClass() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyClass;
 }(getLocalClass(undefined)));
@@ -78,7 +78,7 @@ exports.MyClass = MyClass;
 var MyClass2 = (function (_super) {
     __extends(MyClass2, _super);
     function MyClass2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyClass2;
 }(getExportedClass(undefined)));
@@ -86,7 +86,7 @@ exports.MyClass2 = MyClass2;
 var MyClass3 = (function (_super) {
     __extends(MyClass3, _super);
     function MyClass3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyClass3;
 }(getExportedClass(undefined)));
@@ -94,7 +94,7 @@ exports.MyClass3 = MyClass3;
 var MyClass4 = (function (_super) {
     __extends(MyClass4, _super);
     function MyClass4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyClass4;
 }(getExportedClass(undefined)));
diff --git a/tests/baselines/reference/declarationEmitExpressionInExtends4.js b/tests/baselines/reference/declarationEmitExpressionInExtends4.js
index b90c1275197..acdb2f417b2 100644
--- a/tests/baselines/reference/declarationEmitExpressionInExtends4.js
+++ b/tests/baselines/reference/declarationEmitExpressionInExtends4.js
@@ -33,21 +33,21 @@ function getSomething() {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(getSomething()));
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(SomeUndefinedFunction()));
 var C3 = (function (_super) {
     __extends(C3, _super);
     function C3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C3;
 }(SomeUndefinedFunction));
diff --git a/tests/baselines/reference/declarationEmitNameConflicts3.js b/tests/baselines/reference/declarationEmitNameConflicts3.js
index ffcfead83bf..26eb4300e6b 100644
--- a/tests/baselines/reference/declarationEmitNameConflicts3.js
+++ b/tests/baselines/reference/declarationEmitNameConflicts3.js
@@ -63,7 +63,7 @@ var M;
         var E = (function (_super) {
             __extends(E, _super);
             function E() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return E;
         }(C));
diff --git a/tests/baselines/reference/declarationEmitProtectedMembers.js b/tests/baselines/reference/declarationEmitProtectedMembers.js
index 9ae8e8a2437..48e58bd95ab 100644
--- a/tests/baselines/reference/declarationEmitProtectedMembers.js
+++ b/tests/baselines/reference/declarationEmitProtectedMembers.js
@@ -88,7 +88,7 @@ var C1 = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C2.prototype.f = function () {
         return _super.prototype.f.call(this) + this.x;
@@ -102,7 +102,7 @@ var C2 = (function (_super) {
 var C3 = (function (_super) {
     __extends(C3, _super);
     function C3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C3.prototype.f = function () {
         return _super.prototype.f.call(this);
diff --git a/tests/baselines/reference/declarationEmitThisPredicates01.js b/tests/baselines/reference/declarationEmitThisPredicates01.js
index ad9b7a70373..d2d169132ae 100644
--- a/tests/baselines/reference/declarationEmitThisPredicates01.js
+++ b/tests/baselines/reference/declarationEmitThisPredicates01.js
@@ -28,7 +28,7 @@ exports.C = C;
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/declarationEmitThisPredicatesWithPrivateName01.js b/tests/baselines/reference/declarationEmitThisPredicatesWithPrivateName01.js
index fe7995462ef..4d08678885d 100644
--- a/tests/baselines/reference/declarationEmitThisPredicatesWithPrivateName01.js
+++ b/tests/baselines/reference/declarationEmitThisPredicatesWithPrivateName01.js
@@ -28,7 +28,7 @@ exports.C = C;
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/declareDottedExtend.js b/tests/baselines/reference/declareDottedExtend.js
index 3c7588d2b6c..83917b40dab 100644
--- a/tests/baselines/reference/declareDottedExtend.js
+++ b/tests/baselines/reference/declareDottedExtend.js
@@ -21,14 +21,14 @@ var ab = A.B;
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(ab.C));
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E;
 }(A.B.C));
diff --git a/tests/baselines/reference/decoratorOnClassConstructor4.js b/tests/baselines/reference/decoratorOnClassConstructor4.js
index 22414e89e43..ededadb0c23 100644
--- a/tests/baselines/reference/decoratorOnClassConstructor4.js
+++ b/tests/baselines/reference/decoratorOnClassConstructor4.js
@@ -49,7 +49,7 @@ B = __decorate([
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/decoratorOnClassMethod12.js b/tests/baselines/reference/decoratorOnClassMethod12.js
index 7dd5f698182..bbd0ff5328c 100644
--- a/tests/baselines/reference/decoratorOnClassMethod12.js
+++ b/tests/baselines/reference/decoratorOnClassMethod12.js
@@ -32,7 +32,7 @@ var M;
     var C = (function (_super) {
         __extends(C, _super);
         function C() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         C.prototype.method = function () { };
         return C;
diff --git a/tests/baselines/reference/derivedClassConstructorWithoutSuperCall.js b/tests/baselines/reference/derivedClassConstructorWithoutSuperCall.js
index e76f3445c8e..d3ce94a0df7 100644
--- a/tests/baselines/reference/derivedClassConstructorWithoutSuperCall.js
+++ b/tests/baselines/reference/derivedClassConstructorWithoutSuperCall.js
@@ -47,7 +47,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this;
+        var _this = this;
         return _this;
     }
     return Derived;
@@ -60,7 +60,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        var _this;
+        var _this = this;
         var r2 = function () { return _this = _super.call(this) || this; }; // error for misplaced super call (nested function)
         return _this;
     }
@@ -69,7 +69,7 @@ var Derived2 = (function (_super) {
 var Derived3 = (function (_super) {
     __extends(Derived3, _super);
     function Derived3() {
-        var _this;
+        var _this = this;
         var r = function () { _this = _super.call(this) || this; }; // error
         return _this;
     }
@@ -78,7 +78,7 @@ var Derived3 = (function (_super) {
 var Derived4 = (function (_super) {
     __extends(Derived4, _super);
     function Derived4() {
-        var _this;
+        var _this = this;
         var r = _this = _super.call(this) || this; // ok
         return _this;
     }
diff --git a/tests/baselines/reference/derivedClassFunctionOverridesBaseClassAccessor.js b/tests/baselines/reference/derivedClassFunctionOverridesBaseClassAccessor.js
index 7f6b83593ca..4c37be8b27b 100644
--- a/tests/baselines/reference/derivedClassFunctionOverridesBaseClassAccessor.js
+++ b/tests/baselines/reference/derivedClassFunctionOverridesBaseClassAccessor.js
@@ -38,7 +38,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.prototype.x = function () {
         return 1;
diff --git a/tests/baselines/reference/derivedClassIncludesInheritedMembers.js b/tests/baselines/reference/derivedClassIncludesInheritedMembers.js
index 8224473cb54..6bcd9ededde 100644
--- a/tests/baselines/reference/derivedClassIncludesInheritedMembers.js
+++ b/tests/baselines/reference/derivedClassIncludesInheritedMembers.js
@@ -68,7 +68,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -89,7 +89,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/derivedClassOverridesIndexersWithAssignmentCompatibility.js b/tests/baselines/reference/derivedClassOverridesIndexersWithAssignmentCompatibility.js
index 4753e395390..e25321ab1e9 100644
--- a/tests/baselines/reference/derivedClassOverridesIndexersWithAssignmentCompatibility.js
+++ b/tests/baselines/reference/derivedClassOverridesIndexersWithAssignmentCompatibility.js
@@ -32,7 +32,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -45,7 +45,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/derivedClassOverridesPrivates.js b/tests/baselines/reference/derivedClassOverridesPrivates.js
index 1a58c038fea..2544dc2a6c9 100644
--- a/tests/baselines/reference/derivedClassOverridesPrivates.js
+++ b/tests/baselines/reference/derivedClassOverridesPrivates.js
@@ -29,7 +29,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -41,7 +41,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/derivedClassOverridesProtectedMembers2.js b/tests/baselines/reference/derivedClassOverridesProtectedMembers2.js
index 6797eef0e77..6e69a2bf996 100644
--- a/tests/baselines/reference/derivedClassOverridesProtectedMembers2.js
+++ b/tests/baselines/reference/derivedClassOverridesProtectedMembers2.js
@@ -131,7 +131,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/derivedClassOverridesProtectedMembers4.js b/tests/baselines/reference/derivedClassOverridesProtectedMembers4.js
index 06f80997600..49befa2566a 100644
--- a/tests/baselines/reference/derivedClassOverridesProtectedMembers4.js
+++ b/tests/baselines/reference/derivedClassOverridesProtectedMembers4.js
@@ -30,14 +30,14 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived1;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived1));
diff --git a/tests/baselines/reference/derivedClassOverridesPublicMembers.js b/tests/baselines/reference/derivedClassOverridesPublicMembers.js
index 7943d904dea..3a044f88831 100644
--- a/tests/baselines/reference/derivedClassOverridesPublicMembers.js
+++ b/tests/baselines/reference/derivedClassOverridesPublicMembers.js
@@ -129,7 +129,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/derivedClassOverridesWithoutSubtype.js b/tests/baselines/reference/derivedClassOverridesWithoutSubtype.js
index e42ff9c9e1d..eecdebae690 100644
--- a/tests/baselines/reference/derivedClassOverridesWithoutSubtype.js
+++ b/tests/baselines/reference/derivedClassOverridesWithoutSubtype.js
@@ -37,7 +37,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -49,7 +49,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/derivedClassParameterProperties.js b/tests/baselines/reference/derivedClassParameterProperties.js
index 27dcc4b7d5d..f724fc51149 100644
--- a/tests/baselines/reference/derivedClassParameterProperties.js
+++ b/tests/baselines/reference/derivedClassParameterProperties.js
@@ -109,7 +109,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived(y) {
-        var _this;
+        var _this = this;
         var a = 1;
         _this = _super.call(this) || this; // ok
         return _this;
@@ -119,7 +119,7 @@ var Derived = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2(y) {
-        var _this;
+        var _this = this;
         _this.y = y;
         var a = 1;
         _this = _super.call(this) || this; // error
@@ -140,7 +140,7 @@ var Derived3 = (function (_super) {
 var Derived4 = (function (_super) {
     __extends(Derived4, _super);
     function Derived4(y) {
-        var _this;
+        var _this = this;
         _this.a = 1;
         var b = 2;
         _this = _super.call(this) || this; // error
@@ -161,7 +161,7 @@ var Derived5 = (function (_super) {
 var Derived6 = (function (_super) {
     __extends(Derived6, _super);
     function Derived6(y) {
-        var _this;
+        var _this = this;
         _this.a = 1;
         var b = 2;
         _this = _super.call(this) || this; // error: "super" has to be called before "this" accessing
@@ -172,7 +172,7 @@ var Derived6 = (function (_super) {
 var Derived7 = (function (_super) {
     __extends(Derived7, _super);
     function Derived7(y) {
-        var _this;
+        var _this = this;
         _this.a = 1;
         _this.a = 3;
         _this.b = 3;
@@ -201,7 +201,7 @@ var Base2 = (function () {
 var Derived9 = (function (_super) {
     __extends(Derived9, _super);
     function Derived9(y) {
-        var _this;
+        var _this = this;
         _this.a = 1;
         _this.a = 3;
         _this.b = 3;
diff --git a/tests/baselines/reference/derivedClassSuperCallsInNonConstructorMembers.js b/tests/baselines/reference/derivedClassSuperCallsInNonConstructorMembers.js
index b778d7bbca2..1c4d3a88108 100644
--- a/tests/baselines/reference/derivedClassSuperCallsInNonConstructorMembers.js
+++ b/tests/baselines/reference/derivedClassSuperCallsInNonConstructorMembers.js
@@ -46,7 +46,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.a = _this = _super.call(this) || this;
         return _this;
     }
diff --git a/tests/baselines/reference/derivedClassTransitivity.js b/tests/baselines/reference/derivedClassTransitivity.js
index a76ac8101a0..0771054b475 100644
--- a/tests/baselines/reference/derivedClassTransitivity.js
+++ b/tests/baselines/reference/derivedClassTransitivity.js
@@ -36,7 +36,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.foo = function () { }; // ok to drop parameters
     return D;
@@ -44,7 +44,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.foo = function (x) { }; // ok to add optional parameters
     return E;
diff --git a/tests/baselines/reference/derivedClassTransitivity2.js b/tests/baselines/reference/derivedClassTransitivity2.js
index a3894863696..fb4119f04ca 100644
--- a/tests/baselines/reference/derivedClassTransitivity2.js
+++ b/tests/baselines/reference/derivedClassTransitivity2.js
@@ -36,7 +36,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.foo = function (x) { }; // ok to drop parameters
     return D;
@@ -44,7 +44,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.foo = function (x, y) { }; // ok to add optional parameters
     return E;
diff --git a/tests/baselines/reference/derivedClassTransitivity3.js b/tests/baselines/reference/derivedClassTransitivity3.js
index 71dfecb346f..d1df028fcf3 100644
--- a/tests/baselines/reference/derivedClassTransitivity3.js
+++ b/tests/baselines/reference/derivedClassTransitivity3.js
@@ -36,7 +36,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.foo = function (x) { }; // ok to drop parameters
     return D;
@@ -44,7 +44,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.foo = function (x, y) { }; // ok to add optional parameters
     return E;
diff --git a/tests/baselines/reference/derivedClassTransitivity4.js b/tests/baselines/reference/derivedClassTransitivity4.js
index 0030ce702d8..f7a6814238e 100644
--- a/tests/baselines/reference/derivedClassTransitivity4.js
+++ b/tests/baselines/reference/derivedClassTransitivity4.js
@@ -36,7 +36,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.foo = function () { }; // ok to drop parameters
     return D;
@@ -44,7 +44,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.foo = function (x) { }; // ok to add optional parameters
     return E;
diff --git a/tests/baselines/reference/derivedClassWithAny.js b/tests/baselines/reference/derivedClassWithAny.js
index 2a199e55861..39f998a71a6 100644
--- a/tests/baselines/reference/derivedClassWithAny.js
+++ b/tests/baselines/reference/derivedClassWithAny.js
@@ -91,7 +91,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(D.prototype, "X", {
         get: function () {
@@ -119,7 +119,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(E.prototype, "X", {
         get: function () { return ''; },
diff --git a/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingProtectedInstance.js b/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingProtectedInstance.js
index 0542815c4e4..efcee63fe6b 100644
--- a/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingProtectedInstance.js
+++ b/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingProtectedInstance.js
@@ -46,7 +46,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.prototype.fn = function () {
         return '';
diff --git a/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingPublicInstance.js b/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingPublicInstance.js
index 41869cad416..0672f888701 100644
--- a/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingPublicInstance.js
+++ b/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingPublicInstance.js
@@ -56,7 +56,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.prototype.fn = function () {
         return '';
diff --git a/tests/baselines/reference/derivedClassWithPrivateStaticShadowingProtectedStatic.js b/tests/baselines/reference/derivedClassWithPrivateStaticShadowingProtectedStatic.js
index 10ae3cb35c8..bfc273eb054 100644
--- a/tests/baselines/reference/derivedClassWithPrivateStaticShadowingProtectedStatic.js
+++ b/tests/baselines/reference/derivedClassWithPrivateStaticShadowingProtectedStatic.js
@@ -45,7 +45,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.fn = function () {
         return '';
diff --git a/tests/baselines/reference/derivedClassWithPrivateStaticShadowingPublicStatic.js b/tests/baselines/reference/derivedClassWithPrivateStaticShadowingPublicStatic.js
index 3f2c2a3b811..debe82a7b6e 100644
--- a/tests/baselines/reference/derivedClassWithPrivateStaticShadowingPublicStatic.js
+++ b/tests/baselines/reference/derivedClassWithPrivateStaticShadowingPublicStatic.js
@@ -58,7 +58,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.fn = function () {
         return '';
diff --git a/tests/baselines/reference/derivedClassWithoutExplicitConstructor.js b/tests/baselines/reference/derivedClassWithoutExplicitConstructor.js
index 7a6a7ecbb63..4bb883ec5ce 100644
--- a/tests/baselines/reference/derivedClassWithoutExplicitConstructor.js
+++ b/tests/baselines/reference/derivedClassWithoutExplicitConstructor.js
@@ -41,7 +41,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = 1;
         _this.y = 'hello';
         return _this;
@@ -59,7 +59,7 @@ var Base2 = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = 2;
         _this.y = null;
         return _this;
diff --git a/tests/baselines/reference/derivedClassWithoutExplicitConstructor2.js b/tests/baselines/reference/derivedClassWithoutExplicitConstructor2.js
index 62beb4bf28f..007f0f59a42 100644
--- a/tests/baselines/reference/derivedClassWithoutExplicitConstructor2.js
+++ b/tests/baselines/reference/derivedClassWithoutExplicitConstructor2.js
@@ -49,7 +49,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = 1;
         _this.y = 'hello';
         return _this;
@@ -69,7 +69,7 @@ var Base2 = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = 2;
         _this.y = null;
         return _this;
diff --git a/tests/baselines/reference/derivedClassWithoutExplicitConstructor3.js b/tests/baselines/reference/derivedClassWithoutExplicitConstructor3.js
index c96d0c96723..19bc3fc8790 100644
--- a/tests/baselines/reference/derivedClassWithoutExplicitConstructor3.js
+++ b/tests/baselines/reference/derivedClassWithoutExplicitConstructor3.js
@@ -73,7 +73,7 @@ var Derived = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = 1;
         _this.y = 'hello';
         return _this;
@@ -102,7 +102,7 @@ var D = (function (_super) {
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = 2;
         _this.y = null;
         return _this;
diff --git a/tests/baselines/reference/derivedClasses.js b/tests/baselines/reference/derivedClasses.js
index 3e097a9b139..6aeeca78fce 100644
--- a/tests/baselines/reference/derivedClasses.js
+++ b/tests/baselines/reference/derivedClasses.js
@@ -39,7 +39,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var Red = (function (_super) {
     __extends(Red, _super);
     function Red() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Red.prototype.shade = function () {
         var _this = this;
@@ -58,7 +58,7 @@ var Color = (function () {
 var Blue = (function (_super) {
     __extends(Blue, _super);
     function Blue() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Blue.prototype.shade = function () {
         var _this = this;
diff --git a/tests/baselines/reference/derivedGenericClassWithAny.js b/tests/baselines/reference/derivedGenericClassWithAny.js
index 1822f3fcc47..912eb565fd9 100644
--- a/tests/baselines/reference/derivedGenericClassWithAny.js
+++ b/tests/baselines/reference/derivedGenericClassWithAny.js
@@ -64,7 +64,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(D.prototype, "X", {
         get: function () {
@@ -92,7 +92,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(E.prototype, "X", {
         get: function () { return ''; } // error
diff --git a/tests/baselines/reference/derivedTypeAccessesHiddenBaseCallViaSuperPropertyAccess.js b/tests/baselines/reference/derivedTypeAccessesHiddenBaseCallViaSuperPropertyAccess.js
index c17922e05ee..0460aab8c7e 100644
--- a/tests/baselines/reference/derivedTypeAccessesHiddenBaseCallViaSuperPropertyAccess.js
+++ b/tests/baselines/reference/derivedTypeAccessesHiddenBaseCallViaSuperPropertyAccess.js
@@ -34,7 +34,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.prototype.foo = function (x) {
         return null;
diff --git a/tests/baselines/reference/derivedTypeDoesNotRequireExtendsClause.js b/tests/baselines/reference/derivedTypeDoesNotRequireExtendsClause.js
index 6fe690fd692..f47c4c3803a 100644
--- a/tests/baselines/reference/derivedTypeDoesNotRequireExtendsClause.js
+++ b/tests/baselines/reference/derivedTypeDoesNotRequireExtendsClause.js
@@ -39,7 +39,7 @@ var Derived = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/emitThisInSuperMethodCall.js b/tests/baselines/reference/emitThisInSuperMethodCall.js
index 1f7ed8bfa94..1fce7faee20 100644
--- a/tests/baselines/reference/emitThisInSuperMethodCall.js
+++ b/tests/baselines/reference/emitThisInSuperMethodCall.js
@@ -43,7 +43,7 @@ var User = (function () {
 var RegisteredUser = (function (_super) {
     __extends(RegisteredUser, _super);
     function RegisteredUser() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     RegisteredUser.prototype.f = function () {
         (function () {
diff --git a/tests/baselines/reference/emptyModuleName.js b/tests/baselines/reference/emptyModuleName.js
index 3ed21cf217a..89895bc4e4b 100644
--- a/tests/baselines/reference/emptyModuleName.js
+++ b/tests/baselines/reference/emptyModuleName.js
@@ -14,7 +14,7 @@ var A = require("");
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/errorForwardReferenceForwadingConstructor.js b/tests/baselines/reference/errorForwardReferenceForwadingConstructor.js
index ed2e1aa7f06..42e57602c88 100644
--- a/tests/baselines/reference/errorForwardReferenceForwadingConstructor.js
+++ b/tests/baselines/reference/errorForwardReferenceForwadingConstructor.js
@@ -30,7 +30,7 @@ var base = (function () {
 var derived = (function (_super) {
     __extends(derived, _super);
     function derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return derived;
 }(base));
diff --git a/tests/baselines/reference/errorSuperCalls.js b/tests/baselines/reference/errorSuperCalls.js
index 720894e50c0..bdad114da6d 100644
--- a/tests/baselines/reference/errorSuperCalls.js
+++ b/tests/baselines/reference/errorSuperCalls.js
@@ -132,7 +132,7 @@ var Derived = (function (_super) {
     __extends(Derived, _super);
     //super call with type arguments 
     function Derived() {
-        var _this;
+        var _this = this;
         _super.prototype..call(_this);
         _this = _super.call(this) || this;
         return _this;
@@ -147,7 +147,7 @@ var OtherBase = (function () {
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         //super call in class member initializer of derived type
         _this.t = _this = _super.call(this) || this;
         return _this;
diff --git a/tests/baselines/reference/errorSuperPropertyAccess.js b/tests/baselines/reference/errorSuperPropertyAccess.js
index e12a758b053..9ff7b0df9b3 100644
--- a/tests/baselines/reference/errorSuperPropertyAccess.js
+++ b/tests/baselines/reference/errorSuperPropertyAccess.js
@@ -247,7 +247,7 @@ var SomeDerived2 = (function (_super) {
 var SomeDerived3 = (function (_super) {
     __extends(SomeDerived3, _super);
     function SomeDerived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     SomeDerived3.fn = function () {
         _super.publicStaticMember = 3;
diff --git a/tests/baselines/reference/errorsInGenericTypeReference.js b/tests/baselines/reference/errorsInGenericTypeReference.js
index 6dd9f62edcb..a5e9a55b128 100644
--- a/tests/baselines/reference/errorsInGenericTypeReference.js
+++ b/tests/baselines/reference/errorsInGenericTypeReference.js
@@ -135,7 +135,7 @@ var testClass6 = (function () {
 var testClass7 = (function (_super) {
     __extends(testClass7, _super);
     function testClass7() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return testClass7;
 }(Foo)); // error: could not find symbol V
diff --git a/tests/baselines/reference/es6ClassSuperCodegenBug.js b/tests/baselines/reference/es6ClassSuperCodegenBug.js
index 2eec250211e..e3dbcd226e8 100644
--- a/tests/baselines/reference/es6ClassSuperCodegenBug.js
+++ b/tests/baselines/reference/es6ClassSuperCodegenBug.js
@@ -28,7 +28,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        var _this;
+        var _this = this;
         if (true) {
             _this = _super.call(this, 'a1', 'b1') || this;
         }
diff --git a/tests/baselines/reference/es6ClassTest2.js b/tests/baselines/reference/es6ClassTest2.js
index 533b332422d..ca9706334eb 100644
--- a/tests/baselines/reference/es6ClassTest2.js
+++ b/tests/baselines/reference/es6ClassTest2.js
@@ -314,7 +314,7 @@ var BaseClassWithConstructor = (function () {
 var ChildClassWithoutConstructor = (function (_super) {
     __extends(ChildClassWithoutConstructor, _super);
     function ChildClassWithoutConstructor() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ChildClassWithoutConstructor;
 }(BaseClassWithConstructor));
diff --git a/tests/baselines/reference/es6ClassTest7.js b/tests/baselines/reference/es6ClassTest7.js
index f786fce4461..2dfcb32e5eb 100644
--- a/tests/baselines/reference/es6ClassTest7.js
+++ b/tests/baselines/reference/es6ClassTest7.js
@@ -17,7 +17,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var Bar = (function (_super) {
     __extends(Bar, _super);
     function Bar() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Bar;
 }(M.Foo));
diff --git a/tests/baselines/reference/exportAssignmentOfGenericType1.js b/tests/baselines/reference/exportAssignmentOfGenericType1.js
index 7c1831ecac4..ae7efff7028 100644
--- a/tests/baselines/reference/exportAssignmentOfGenericType1.js
+++ b/tests/baselines/reference/exportAssignmentOfGenericType1.js
@@ -34,7 +34,7 @@ define(["require", "exports", "exportAssignmentOfGenericType1_0"], function (req
     var M = (function (_super) {
         __extends(M, _super);
         function M() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return M;
     }(q));
diff --git a/tests/baselines/reference/exportDeclarationInInternalModule.js b/tests/baselines/reference/exportDeclarationInInternalModule.js
index b6d6d982a32..a779deea82f 100644
--- a/tests/baselines/reference/exportDeclarationInInternalModule.js
+++ b/tests/baselines/reference/exportDeclarationInInternalModule.js
@@ -32,7 +32,7 @@ var Bbb = (function () {
 var Aaa = (function (_super) {
     __extends(Aaa, _super);
     function Aaa() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Aaa;
 }(Bbb));
diff --git a/tests/baselines/reference/extBaseClass1.js b/tests/baselines/reference/extBaseClass1.js
index 91dfba7a9bf..11ce0fe8634 100644
--- a/tests/baselines/reference/extBaseClass1.js
+++ b/tests/baselines/reference/extBaseClass1.js
@@ -37,7 +37,7 @@ var M;
     var C = (function (_super) {
         __extends(C, _super);
         function C() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return C;
     }(B));
@@ -47,7 +47,7 @@ var M;
     var C2 = (function (_super) {
         __extends(C2, _super);
         function C2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return C2;
     }(M.B));
@@ -58,7 +58,7 @@ var N;
     var C3 = (function (_super) {
         __extends(C3, _super);
         function C3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return C3;
     }(M.B));
diff --git a/tests/baselines/reference/extBaseClass2.js b/tests/baselines/reference/extBaseClass2.js
index 3ab217eb019..df22b9a6294 100644
--- a/tests/baselines/reference/extBaseClass2.js
+++ b/tests/baselines/reference/extBaseClass2.js
@@ -21,7 +21,7 @@ var N;
     var C4 = (function (_super) {
         __extends(C4, _super);
         function C4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return C4;
     }(M.B));
@@ -32,7 +32,7 @@ var M;
     var C5 = (function (_super) {
         __extends(C5, _super);
         function C5() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return C5;
     }(B));
diff --git a/tests/baselines/reference/extendAndImplementTheSameBaseType.js b/tests/baselines/reference/extendAndImplementTheSameBaseType.js
index 74bbf3a27ac..29b3dcb199a 100644
--- a/tests/baselines/reference/extendAndImplementTheSameBaseType.js
+++ b/tests/baselines/reference/extendAndImplementTheSameBaseType.js
@@ -28,7 +28,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.baz = function () { };
     return D;
diff --git a/tests/baselines/reference/extendAndImplementTheSameBaseType2.js b/tests/baselines/reference/extendAndImplementTheSameBaseType2.js
index fa7963487d5..7537ecd3f99 100644
--- a/tests/baselines/reference/extendAndImplementTheSameBaseType2.js
+++ b/tests/baselines/reference/extendAndImplementTheSameBaseType2.js
@@ -33,7 +33,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.baz = function () { };
     return D;
diff --git a/tests/baselines/reference/extendBaseClassBeforeItsDeclared.js b/tests/baselines/reference/extendBaseClassBeforeItsDeclared.js
index 596ab319b2c..c5f4281c360 100644
--- a/tests/baselines/reference/extendBaseClassBeforeItsDeclared.js
+++ b/tests/baselines/reference/extendBaseClassBeforeItsDeclared.js
@@ -12,7 +12,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var derived = (function (_super) {
     __extends(derived, _super);
     function derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return derived;
 }(base));
diff --git a/tests/baselines/reference/extendClassExpressionFromModule.js b/tests/baselines/reference/extendClassExpressionFromModule.js
index 895cdedfaff..9865690859a 100644
--- a/tests/baselines/reference/extendClassExpressionFromModule.js
+++ b/tests/baselines/reference/extendClassExpressionFromModule.js
@@ -31,7 +31,7 @@ var x = foo1;
 var y = (function (_super) {
     __extends(y, _super);
     function y() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return y;
 }(x));
diff --git a/tests/baselines/reference/extendConstructSignatureInInterface.js b/tests/baselines/reference/extendConstructSignatureInInterface.js
index 4bf92dd0315..f0f8edb87ff 100644
--- a/tests/baselines/reference/extendConstructSignatureInInterface.js
+++ b/tests/baselines/reference/extendConstructSignatureInInterface.js
@@ -20,7 +20,7 @@ var CStatic;
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E;
 }(CStatic));
diff --git a/tests/baselines/reference/extendNonClassSymbol1.js b/tests/baselines/reference/extendNonClassSymbol1.js
index b23b601bc29..3963ddcae65 100644
--- a/tests/baselines/reference/extendNonClassSymbol1.js
+++ b/tests/baselines/reference/extendNonClassSymbol1.js
@@ -19,7 +19,7 @@ var x = A;
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(x)); // error, could not find symbol xs
diff --git a/tests/baselines/reference/extendNonClassSymbol2.js b/tests/baselines/reference/extendNonClassSymbol2.js
index 78dfaa91827..6cdebcc3c4d 100644
--- a/tests/baselines/reference/extendNonClassSymbol2.js
+++ b/tests/baselines/reference/extendNonClassSymbol2.js
@@ -18,7 +18,7 @@ var x = new Foo(); // legal, considered a constructor function
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(Foo)); // error, could not find symbol Foo
diff --git a/tests/baselines/reference/extendPrivateConstructorClass.js b/tests/baselines/reference/extendPrivateConstructorClass.js
index 8893e9735ff..ee4b45357ea 100644
--- a/tests/baselines/reference/extendPrivateConstructorClass.js
+++ b/tests/baselines/reference/extendPrivateConstructorClass.js
@@ -18,7 +18,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(abc.XYZ));
diff --git a/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.js b/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.js
index da081154d8a..eeebba01097 100644
--- a/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.js
+++ b/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.js
@@ -51,7 +51,7 @@ var Backbone = require("./extendingClassFromAliasAndUsageInIndexer_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
@@ -67,7 +67,7 @@ var Backbone = require("./extendingClassFromAliasAndUsageInIndexer_backbone");
 var VisualizationModel = (function (_super) {
     __extends(VisualizationModel, _super);
     function VisualizationModel() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return VisualizationModel;
 }(Backbone.Model));
diff --git a/tests/baselines/reference/extendsClauseAlreadySeen.js b/tests/baselines/reference/extendsClauseAlreadySeen.js
index 267cd86eed0..ab99c984042 100644
--- a/tests/baselines/reference/extendsClauseAlreadySeen.js
+++ b/tests/baselines/reference/extendsClauseAlreadySeen.js
@@ -20,7 +20,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.baz = function () { };
     return D;
diff --git a/tests/baselines/reference/extendsClauseAlreadySeen2.js b/tests/baselines/reference/extendsClauseAlreadySeen2.js
index 76fbc3365af..40f3a068f37 100644
--- a/tests/baselines/reference/extendsClauseAlreadySeen2.js
+++ b/tests/baselines/reference/extendsClauseAlreadySeen2.js
@@ -20,7 +20,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.baz = function () { };
     return D;
diff --git a/tests/baselines/reference/fluentClasses.js b/tests/baselines/reference/fluentClasses.js
index ac44416e133..55ea547e466 100644
--- a/tests/baselines/reference/fluentClasses.js
+++ b/tests/baselines/reference/fluentClasses.js
@@ -35,7 +35,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.bar = function () {
         return this;
@@ -45,7 +45,7 @@ var B = (function (_super) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.baz = function () {
         return this;
diff --git a/tests/baselines/reference/for-inStatements.js b/tests/baselines/reference/for-inStatements.js
index 15d771bf587..94b860dcd91 100644
--- a/tests/baselines/reference/for-inStatements.js
+++ b/tests/baselines/reference/for-inStatements.js
@@ -126,7 +126,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.boz = function () {
         for (var x in this.biz()) { }
diff --git a/tests/baselines/reference/for-inStatementsInvalid.js b/tests/baselines/reference/for-inStatementsInvalid.js
index d1181760a36..0a7272a702c 100644
--- a/tests/baselines/reference/for-inStatementsInvalid.js
+++ b/tests/baselines/reference/for-inStatementsInvalid.js
@@ -107,7 +107,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.boz = function () {
         for (var x in this.biz()) { }
diff --git a/tests/baselines/reference/forStatementsMultipleInvalidDecl.js b/tests/baselines/reference/forStatementsMultipleInvalidDecl.js
index 3666ad930a6..75185335788 100644
--- a/tests/baselines/reference/forStatementsMultipleInvalidDecl.js
+++ b/tests/baselines/reference/forStatementsMultipleInvalidDecl.js
@@ -68,7 +68,7 @@ var C = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(C));
diff --git a/tests/baselines/reference/functionImplementationErrors.js b/tests/baselines/reference/functionImplementationErrors.js
index 433418af41d..0c57117971c 100644
--- a/tests/baselines/reference/functionImplementationErrors.js
+++ b/tests/baselines/reference/functionImplementationErrors.js
@@ -134,14 +134,14 @@ var AnotherClass = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived1;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/functionImplementations.js b/tests/baselines/reference/functionImplementations.js
index 86636b84a87..7fdb541adb8 100644
--- a/tests/baselines/reference/functionImplementations.js
+++ b/tests/baselines/reference/functionImplementations.js
@@ -236,7 +236,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -287,7 +287,7 @@ function f6() {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/functionSubtypingOfVarArgs.js b/tests/baselines/reference/functionSubtypingOfVarArgs.js
index 55917962184..9e3962af717 100644
--- a/tests/baselines/reference/functionSubtypingOfVarArgs.js
+++ b/tests/baselines/reference/functionSubtypingOfVarArgs.js
@@ -32,7 +32,7 @@ var EventBase = (function () {
 var StringEvent = (function (_super) {
     __extends(StringEvent, _super);
     function StringEvent() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     StringEvent.prototype.add = function (listener) {
         _super.prototype.add.call(this, listener);
diff --git a/tests/baselines/reference/functionSubtypingOfVarArgs2.js b/tests/baselines/reference/functionSubtypingOfVarArgs2.js
index a676316459f..bcb6162e0e2 100644
--- a/tests/baselines/reference/functionSubtypingOfVarArgs2.js
+++ b/tests/baselines/reference/functionSubtypingOfVarArgs2.js
@@ -32,7 +32,7 @@ var EventBase = (function () {
 var StringEvent = (function (_super) {
     __extends(StringEvent, _super);
     function StringEvent() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     StringEvent.prototype.add = function (listener) {
         _super.prototype.add.call(this, listener);
diff --git a/tests/baselines/reference/generatedContextualTyping.js b/tests/baselines/reference/generatedContextualTyping.js
index 2a6911d9cf5..1b329f1093e 100644
--- a/tests/baselines/reference/generatedContextualTyping.js
+++ b/tests/baselines/reference/generatedContextualTyping.js
@@ -369,14 +369,14 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived1;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/genericBaseClassLiteralProperty.js b/tests/baselines/reference/genericBaseClassLiteralProperty.js
index a075eff9550..63e2519e6c7 100644
--- a/tests/baselines/reference/genericBaseClassLiteralProperty.js
+++ b/tests/baselines/reference/genericBaseClassLiteralProperty.js
@@ -26,7 +26,7 @@ var BaseClass = (function () {
 var SubClass = (function (_super) {
     __extends(SubClass, _super);
     function SubClass() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     SubClass.prototype.Error = function () {
         var x = this._getValue1();
diff --git a/tests/baselines/reference/genericBaseClassLiteralProperty2.js b/tests/baselines/reference/genericBaseClassLiteralProperty2.js
index 2b562742bf7..e2fc062b4d8 100644
--- a/tests/baselines/reference/genericBaseClassLiteralProperty2.js
+++ b/tests/baselines/reference/genericBaseClassLiteralProperty2.js
@@ -35,7 +35,7 @@ var BaseCollection2 = (function () {
 var DataView2 = (function (_super) {
     __extends(DataView2, _super);
     function DataView2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     DataView2.prototype.fillItems = function (item) {
         this._itemsByKey['dummy'] = item;
diff --git a/tests/baselines/reference/genericCallWithConstraintsTypeArgumentInference.js b/tests/baselines/reference/genericCallWithConstraintsTypeArgumentInference.js
index afef6224ba1..7b9433508a0 100644
--- a/tests/baselines/reference/genericCallWithConstraintsTypeArgumentInference.js
+++ b/tests/baselines/reference/genericCallWithConstraintsTypeArgumentInference.js
@@ -122,14 +122,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
diff --git a/tests/baselines/reference/genericCallWithObjectTypeArgs2.js b/tests/baselines/reference/genericCallWithObjectTypeArgs2.js
index 7b621b3ffd9..ca3806df629 100644
--- a/tests/baselines/reference/genericCallWithObjectTypeArgs2.js
+++ b/tests/baselines/reference/genericCallWithObjectTypeArgs2.js
@@ -46,14 +46,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints2.js b/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints2.js
index 892cda0ee2d..59f2e53cdf8 100644
--- a/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints2.js
+++ b/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints2.js
@@ -54,7 +54,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints3.js b/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints3.js
index addfbc756a8..3730c756aad 100644
--- a/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints3.js
+++ b/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints3.js
@@ -52,14 +52,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/genericCallbacksAndClassHierarchy.js b/tests/baselines/reference/genericCallbacksAndClassHierarchy.js
index c2ad2ba29a3..f3026144ab2 100644
--- a/tests/baselines/reference/genericCallbacksAndClassHierarchy.js
+++ b/tests/baselines/reference/genericCallbacksAndClassHierarchy.js
@@ -46,7 +46,7 @@ var M;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(C1));
diff --git a/tests/baselines/reference/genericClassExpressionInFunction.js b/tests/baselines/reference/genericClassExpressionInFunction.js
index dc574dedb00..1a978687427 100644
--- a/tests/baselines/reference/genericClassExpressionInFunction.js
+++ b/tests/baselines/reference/genericClassExpressionInFunction.js
@@ -47,7 +47,7 @@ function B1() {
     return (function (_super) {
         __extends(class_1, _super);
         function class_1() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class_1;
     }(A));
@@ -57,7 +57,7 @@ var B2 = (function () {
         this.anon = (function (_super) {
             __extends(class_2, _super);
             function class_2() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return class_2;
         }(A));
@@ -68,7 +68,7 @@ function B3() {
     return (function (_super) {
         __extends(Inner, _super);
         function Inner() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Inner;
     }(A));
@@ -77,14 +77,14 @@ function B3() {
 var K = (function (_super) {
     __extends(K, _super);
     function K() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return K;
 }(B1()));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }((new B2().anon)));
@@ -92,7 +92,7 @@ var b3Number = B3();
 var S = (function (_super) {
     __extends(S, _super);
     function S() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return S;
 }(b3Number));
diff --git a/tests/baselines/reference/genericClassInheritsConstructorFromNonGenericClass.js b/tests/baselines/reference/genericClassInheritsConstructorFromNonGenericClass.js
index 1f3a6e17f14..c8012596bac 100644
--- a/tests/baselines/reference/genericClassInheritsConstructorFromNonGenericClass.js
+++ b/tests/baselines/reference/genericClassInheritsConstructorFromNonGenericClass.js
@@ -14,14 +14,14 @@ var __extends = (this && this.__extends) || function (d, b) {
 var A = (function (_super) {
     __extends(A, _super);
     function A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A;
 }(B));
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(C));
diff --git a/tests/baselines/reference/genericClassStaticMethod.js b/tests/baselines/reference/genericClassStaticMethod.js
index 4609e3bc9db..33440963f62 100644
--- a/tests/baselines/reference/genericClassStaticMethod.js
+++ b/tests/baselines/reference/genericClassStaticMethod.js
@@ -26,7 +26,7 @@ var Foo = (function () {
 var Bar = (function (_super) {
     __extends(Bar, _super);
     function Bar() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Bar.getFoo = function () {
     };
diff --git a/tests/baselines/reference/genericClasses3.js b/tests/baselines/reference/genericClasses3.js
index 5371e2479aa..697edbd3fab 100644
--- a/tests/baselines/reference/genericClasses3.js
+++ b/tests/baselines/reference/genericClasses3.js
@@ -31,7 +31,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(B));
diff --git a/tests/baselines/reference/genericDerivedTypeWithSpecializedBase.js b/tests/baselines/reference/genericDerivedTypeWithSpecializedBase.js
index 1b455073196..a5d7a3a7c05 100644
--- a/tests/baselines/reference/genericDerivedTypeWithSpecializedBase.js
+++ b/tests/baselines/reference/genericDerivedTypeWithSpecializedBase.js
@@ -26,7 +26,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/genericDerivedTypeWithSpecializedBase2.js b/tests/baselines/reference/genericDerivedTypeWithSpecializedBase2.js
index 0abd655e1da..d6473df6529 100644
--- a/tests/baselines/reference/genericDerivedTypeWithSpecializedBase2.js
+++ b/tests/baselines/reference/genericDerivedTypeWithSpecializedBase2.js
@@ -26,7 +26,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/genericInheritedDefaultConstructors.js b/tests/baselines/reference/genericInheritedDefaultConstructors.js
index 059a3213b7a..7f213f3b15a 100644
--- a/tests/baselines/reference/genericInheritedDefaultConstructors.js
+++ b/tests/baselines/reference/genericInheritedDefaultConstructors.js
@@ -24,7 +24,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/genericPrototypeProperty2.js b/tests/baselines/reference/genericPrototypeProperty2.js
index eac025cce9b..ad80ef6664b 100644
--- a/tests/baselines/reference/genericPrototypeProperty2.js
+++ b/tests/baselines/reference/genericPrototypeProperty2.js
@@ -29,7 +29,7 @@ var BaseEvent = (function () {
 var MyEvent = (function (_super) {
     __extends(MyEvent, _super);
     function MyEvent() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyEvent;
 }(BaseEvent));
@@ -41,7 +41,7 @@ var BaseEventWrapper = (function () {
 var MyEventWrapper = (function (_super) {
     __extends(MyEventWrapper, _super);
     function MyEventWrapper() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyEventWrapper;
 }(BaseEventWrapper));
diff --git a/tests/baselines/reference/genericPrototypeProperty3.js b/tests/baselines/reference/genericPrototypeProperty3.js
index 9e3ede0019d..f40a225c2ab 100644
--- a/tests/baselines/reference/genericPrototypeProperty3.js
+++ b/tests/baselines/reference/genericPrototypeProperty3.js
@@ -28,7 +28,7 @@ var BaseEvent = (function () {
 var MyEvent = (function (_super) {
     __extends(MyEvent, _super);
     function MyEvent() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyEvent;
 }(BaseEvent));
@@ -40,7 +40,7 @@ var BaseEventWrapper = (function () {
 var MyEventWrapper = (function (_super) {
     __extends(MyEventWrapper, _super);
     function MyEventWrapper() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyEventWrapper;
 }(BaseEventWrapper));
diff --git a/tests/baselines/reference/genericRecursiveImplicitConstructorErrors2.js b/tests/baselines/reference/genericRecursiveImplicitConstructorErrors2.js
index 401a2e94b68..003c4889929 100644
--- a/tests/baselines/reference/genericRecursiveImplicitConstructorErrors2.js
+++ b/tests/baselines/reference/genericRecursiveImplicitConstructorErrors2.js
@@ -57,7 +57,7 @@ var TypeScript2;
     var PullTypeSymbol = (function (_super) {
         __extends(PullTypeSymbol, _super);
         function PullTypeSymbol() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return PullTypeSymbol;
     }(PullSymbol));
diff --git a/tests/baselines/reference/genericRecursiveImplicitConstructorErrors3.js b/tests/baselines/reference/genericRecursiveImplicitConstructorErrors3.js
index c7643d4a9a2..60ee6dee616 100644
--- a/tests/baselines/reference/genericRecursiveImplicitConstructorErrors3.js
+++ b/tests/baselines/reference/genericRecursiveImplicitConstructorErrors3.js
@@ -58,7 +58,7 @@ var TypeScript;
     var PullTypeSymbol = (function (_super) {
         __extends(PullTypeSymbol, _super);
         function PullTypeSymbol() {
-            var _this = _super.apply(this, arguments) || this;
+            var _this = _super !== null && _super.apply(this, arguments) || this;
             _this._elementType = null;
             return _this;
         }
diff --git a/tests/baselines/reference/genericTypeAssertions2.js b/tests/baselines/reference/genericTypeAssertions2.js
index 687d593f01e..b728c666014 100644
--- a/tests/baselines/reference/genericTypeAssertions2.js
+++ b/tests/baselines/reference/genericTypeAssertions2.js
@@ -28,7 +28,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.bar = function () {
         return null;
diff --git a/tests/baselines/reference/genericTypeAssertions4.js b/tests/baselines/reference/genericTypeAssertions4.js
index 50dbe5debbd..f694b9b4c54 100644
--- a/tests/baselines/reference/genericTypeAssertions4.js
+++ b/tests/baselines/reference/genericTypeAssertions4.js
@@ -40,7 +40,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.bar = function () { return 1; };
     return B;
@@ -48,7 +48,7 @@ var B = (function (_super) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.baz = function () { return 1; };
     return C;
diff --git a/tests/baselines/reference/genericTypeAssertions6.js b/tests/baselines/reference/genericTypeAssertions6.js
index 7bbd7351f1d..329a78b3cc6 100644
--- a/tests/baselines/reference/genericTypeAssertions6.js
+++ b/tests/baselines/reference/genericTypeAssertions6.js
@@ -44,7 +44,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.g = function (x) {
         var a = x;
diff --git a/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument.js b/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument.js
index cf19feede34..2ebad804fa1 100644
--- a/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument.js
+++ b/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument.js
@@ -60,7 +60,7 @@ var g = function f(x) { var y; return y; };
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
@@ -76,7 +76,7 @@ var M;
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(M.E));
diff --git a/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument2.js b/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument2.js
index 973ee231762..bb75347665a 100644
--- a/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument2.js
+++ b/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument2.js
@@ -55,14 +55,14 @@ var g = function f(x) { var y; return y; };
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(I));
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(M.C));
diff --git a/tests/baselines/reference/genericWithIndexerOfTypeParameterType2.js b/tests/baselines/reference/genericWithIndexerOfTypeParameterType2.js
index d6fb98b67ca..aad5b72ddda 100644
--- a/tests/baselines/reference/genericWithIndexerOfTypeParameterType2.js
+++ b/tests/baselines/reference/genericWithIndexerOfTypeParameterType2.js
@@ -31,7 +31,7 @@ define(["require", "exports"], function (require, exports) {
     var List = (function (_super) {
         __extends(List, _super);
         function List() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         List.prototype.Bar = function () { };
         return List;
@@ -46,7 +46,7 @@ define(["require", "exports"], function (require, exports) {
     var ListItem = (function (_super) {
         __extends(ListItem, _super);
         function ListItem() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return ListItem;
     }(CollectionItem));
diff --git a/tests/baselines/reference/heterogeneousArrayLiterals.js b/tests/baselines/reference/heterogeneousArrayLiterals.js
index 9b15cf743f0..dbc90aba9ed 100644
--- a/tests/baselines/reference/heterogeneousArrayLiterals.js
+++ b/tests/baselines/reference/heterogeneousArrayLiterals.js
@@ -160,14 +160,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/ifDoWhileStatements.js b/tests/baselines/reference/ifDoWhileStatements.js
index 483370bee5c..2377fe48af2 100644
--- a/tests/baselines/reference/ifDoWhileStatements.js
+++ b/tests/baselines/reference/ifDoWhileStatements.js
@@ -177,7 +177,7 @@ var C = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(C));
diff --git a/tests/baselines/reference/illegalSuperCallsInConstructor.js b/tests/baselines/reference/illegalSuperCallsInConstructor.js
index 868d53daad5..95afb9e529b 100644
--- a/tests/baselines/reference/illegalSuperCallsInConstructor.js
+++ b/tests/baselines/reference/illegalSuperCallsInConstructor.js
@@ -34,7 +34,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this;
+        var _this = this;
         var r2 = function () { return _this = _super.call(this) || this; };
         var r3 = function () { _this = _super.call(this) || this; };
         var r4 = function () { _this = _super.call(this) || this; };
diff --git a/tests/baselines/reference/implementClausePrecedingExtends.js b/tests/baselines/reference/implementClausePrecedingExtends.js
index df725cde43a..09ebc1ffc52 100644
--- a/tests/baselines/reference/implementClausePrecedingExtends.js
+++ b/tests/baselines/reference/implementClausePrecedingExtends.js
@@ -16,7 +16,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/implementingAnInterfaceExtendingClassWithPrivates2.js b/tests/baselines/reference/implementingAnInterfaceExtendingClassWithPrivates2.js
index a5a5e02c156..385ce78bc53 100644
--- a/tests/baselines/reference/implementingAnInterfaceExtendingClassWithPrivates2.js
+++ b/tests/baselines/reference/implementingAnInterfaceExtendingClassWithPrivates2.js
@@ -99,21 +99,21 @@ var Foo = (function () {
 var Bar = (function (_super) {
     __extends(Bar, _super);
     function Bar() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Bar;
 }(Foo));
 var Bar2 = (function (_super) {
     __extends(Bar2, _super);
     function Bar2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Bar2;
 }(Foo));
 var Bar3 = (function (_super) {
     __extends(Bar3, _super);
     function Bar3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Bar3;
 }(Foo));
@@ -128,28 +128,28 @@ var M;
     var Baz = (function (_super) {
         __extends(Baz, _super);
         function Baz() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Baz;
     }(Foo));
     var Bar = (function (_super) {
         __extends(Bar, _super);
         function Bar() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Bar;
     }(Foo));
     var Bar2 = (function (_super) {
         __extends(Bar2, _super);
         function Bar2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Bar2;
     }(Foo));
     var Bar3 = (function (_super) {
         __extends(Bar3, _super);
         function Bar3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Bar3;
     }(Foo));
@@ -165,14 +165,14 @@ var M2;
     var Baz = (function (_super) {
         __extends(Baz, _super);
         function Baz() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Baz;
     }(Foo));
     var Bar = (function (_super) {
         __extends(Bar, _super);
         function Bar() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Bar;
     }(Foo));
@@ -183,14 +183,14 @@ var M2;
     var Bar2 = (function (_super) {
         __extends(Bar2, _super);
         function Bar2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Bar2;
     }(Foo));
     var Bar3 = (function (_super) {
         __extends(Bar3, _super);
         function Bar3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Bar3;
     }(Foo));
diff --git a/tests/baselines/reference/implementingAnInterfaceExtendingClassWithProtecteds.js b/tests/baselines/reference/implementingAnInterfaceExtendingClassWithProtecteds.js
index d0f74847141..976f1792998 100644
--- a/tests/baselines/reference/implementingAnInterfaceExtendingClassWithProtecteds.js
+++ b/tests/baselines/reference/implementingAnInterfaceExtendingClassWithProtecteds.js
@@ -75,28 +75,28 @@ var Bar4 = (function () {
 var Bar5 = (function (_super) {
     __extends(Bar5, _super);
     function Bar5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Bar5;
 }(Foo));
 var Bar6 = (function (_super) {
     __extends(Bar6, _super);
     function Bar6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Bar6;
 }(Foo));
 var Bar7 = (function (_super) {
     __extends(Bar7, _super);
     function Bar7() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Bar7;
 }(Foo));
 var Bar8 = (function (_super) {
     __extends(Bar8, _super);
     function Bar8() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Bar8;
 }(Foo));
diff --git a/tests/baselines/reference/importAsBaseClass.js b/tests/baselines/reference/importAsBaseClass.js
index b4f45cac806..284b1536db8 100644
--- a/tests/baselines/reference/importAsBaseClass.js
+++ b/tests/baselines/reference/importAsBaseClass.js
@@ -30,7 +30,7 @@ var Greeter = require("./importAsBaseClass_0");
 var Hello = (function (_super) {
     __extends(Hello, _super);
     function Hello() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Hello;
 }(Greeter));
diff --git a/tests/baselines/reference/importHelpers.js b/tests/baselines/reference/importHelpers.js
index 762f0778945..4de852423ba 100644
--- a/tests/baselines/reference/importHelpers.js
+++ b/tests/baselines/reference/importHelpers.js
@@ -45,7 +45,7 @@ exports.A = A;
 var B = (function (_super) {
     tslib_1.__extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -92,7 +92,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/importHelpersAmd.js b/tests/baselines/reference/importHelpersAmd.js
index fea93840fa9..6054e147386 100644
--- a/tests/baselines/reference/importHelpersAmd.js
+++ b/tests/baselines/reference/importHelpersAmd.js
@@ -32,7 +32,7 @@ define(["require", "exports", "tslib", "./a"], function (require, exports, tslib
     var B = (function (_super) {
         tslib_1.__extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(a_1.A));
diff --git a/tests/baselines/reference/importHelpersInIsolatedModules.js b/tests/baselines/reference/importHelpersInIsolatedModules.js
index 5c395ea0b9f..429a71c1ab8 100644
--- a/tests/baselines/reference/importHelpersInIsolatedModules.js
+++ b/tests/baselines/reference/importHelpersInIsolatedModules.js
@@ -45,7 +45,7 @@ exports.A = A;
 var B = (function (_super) {
     tslib_1.__extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -77,7 +77,7 @@ var A = (function () {
 var B = (function (_super) {
     tslib_1.__extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/importHelpersNoHelpers.js b/tests/baselines/reference/importHelpersNoHelpers.js
index 560e16d1cca..6a60008c6f1 100644
--- a/tests/baselines/reference/importHelpersNoHelpers.js
+++ b/tests/baselines/reference/importHelpersNoHelpers.js
@@ -44,7 +44,7 @@ exports.A = A;
 var B = (function (_super) {
     tslib_1.__extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -94,7 +94,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/importHelpersNoModule.js b/tests/baselines/reference/importHelpersNoModule.js
index 65a004eb66c..99bb3e8656e 100644
--- a/tests/baselines/reference/importHelpersNoModule.js
+++ b/tests/baselines/reference/importHelpersNoModule.js
@@ -37,7 +37,7 @@ exports.A = A;
 var B = (function (_super) {
     tslib_1.__extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -84,7 +84,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/importHelpersOutFile.js b/tests/baselines/reference/importHelpersOutFile.js
index a45f6285782..572115ba4bb 100644
--- a/tests/baselines/reference/importHelpersOutFile.js
+++ b/tests/baselines/reference/importHelpersOutFile.js
@@ -35,7 +35,7 @@ define("b", ["require", "exports", "tslib", "a"], function (require, exports, ts
     var B = (function (_super) {
         tslib_1.__extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(a_1.A));
@@ -46,7 +46,7 @@ define("c", ["require", "exports", "tslib", "a"], function (require, exports, ts
     var C = (function (_super) {
         tslib_2.__extends(C, _super);
         function C() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return C;
     }(a_2.A));
diff --git a/tests/baselines/reference/importHelpersSystem.js b/tests/baselines/reference/importHelpersSystem.js
index 20f2d299c52..b7c10ee3c34 100644
--- a/tests/baselines/reference/importHelpersSystem.js
+++ b/tests/baselines/reference/importHelpersSystem.js
@@ -51,7 +51,7 @@ System.register(["tslib", "./a"], function (exports_1, context_1) {
             B = (function (_super) {
                 tslib_1.__extends(B, _super);
                 function B() {
-                    return _super.apply(this, arguments) || this;
+                    return _super !== null && _super.apply(this, arguments) || this;
                 }
                 return B;
             }(a_1.A));
diff --git a/tests/baselines/reference/importShadowsGlobalName.js b/tests/baselines/reference/importShadowsGlobalName.js
index 34cc0604e7a..a0587662a0d 100644
--- a/tests/baselines/reference/importShadowsGlobalName.js
+++ b/tests/baselines/reference/importShadowsGlobalName.js
@@ -31,7 +31,7 @@ define(["require", "exports", "Foo"], function (require, exports, Error) {
     var Bar = (function (_super) {
         __extends(Bar, _super);
         function Bar() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Bar;
     }(Error));
diff --git a/tests/baselines/reference/importUsedInExtendsList1.js b/tests/baselines/reference/importUsedInExtendsList1.js
index a40c3a51a78..09ac46fdc0b 100644
--- a/tests/baselines/reference/importUsedInExtendsList1.js
+++ b/tests/baselines/reference/importUsedInExtendsList1.js
@@ -31,7 +31,7 @@ var foo = require("./importUsedInExtendsList1_require");
 var Sub = (function (_super) {
     __extends(Sub, _super);
     function Sub() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Sub;
 }(foo.Super));
diff --git a/tests/baselines/reference/indexerConstraints2.js b/tests/baselines/reference/indexerConstraints2.js
index d7357f021d0..d91206c2a99 100644
--- a/tests/baselines/reference/indexerConstraints2.js
+++ b/tests/baselines/reference/indexerConstraints2.js
@@ -42,7 +42,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -55,7 +55,7 @@ var F = (function () {
 var G = (function (_super) {
     __extends(G, _super);
     function G() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return G;
 }(F));
@@ -68,7 +68,7 @@ var H = (function () {
 var I = (function (_super) {
     __extends(I, _super);
     function I() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return I;
 }(H));
@@ -81,7 +81,7 @@ var J = (function () {
 var K = (function (_super) {
     __extends(K, _super);
     function K() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return K;
 }(J));
diff --git a/tests/baselines/reference/indirectSelfReference.js b/tests/baselines/reference/indirectSelfReference.js
index 2f4f37b9b53..9f0fbeea3fe 100644
--- a/tests/baselines/reference/indirectSelfReference.js
+++ b/tests/baselines/reference/indirectSelfReference.js
@@ -11,14 +11,14 @@ var __extends = (this && this.__extends) || function (d, b) {
 var a = (function (_super) {
     __extends(a, _super);
     function a() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return a;
 }(b));
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/indirectSelfReferenceGeneric.js b/tests/baselines/reference/indirectSelfReferenceGeneric.js
index 9171bb0eeb6..f3b9fe2fb8a 100644
--- a/tests/baselines/reference/indirectSelfReferenceGeneric.js
+++ b/tests/baselines/reference/indirectSelfReferenceGeneric.js
@@ -11,14 +11,14 @@ var __extends = (this && this.__extends) || function (d, b) {
 var a = (function (_super) {
     __extends(a, _super);
     function a() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return a;
 }(b));
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/infinitelyExpandingTypesNonGenericBase.js b/tests/baselines/reference/infinitelyExpandingTypesNonGenericBase.js
index ad1a063bfb0..8b9b1e52a9a 100644
--- a/tests/baselines/reference/infinitelyExpandingTypesNonGenericBase.js
+++ b/tests/baselines/reference/infinitelyExpandingTypesNonGenericBase.js
@@ -43,7 +43,7 @@ var Base = (function () {
 var A = (function (_super) {
     __extends(A, _super);
     function A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A;
 }(Base));
diff --git a/tests/baselines/reference/inheritFromGenericTypeParameter.js b/tests/baselines/reference/inheritFromGenericTypeParameter.js
index 40e6abd3e53..6495fd73d40 100644
--- a/tests/baselines/reference/inheritFromGenericTypeParameter.js
+++ b/tests/baselines/reference/inheritFromGenericTypeParameter.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(T));
diff --git a/tests/baselines/reference/inheritSameNamePrivatePropertiesFromSameOrigin.js b/tests/baselines/reference/inheritSameNamePrivatePropertiesFromSameOrigin.js
index a0874eb1c72..7ff32437d72 100644
--- a/tests/baselines/reference/inheritSameNamePrivatePropertiesFromSameOrigin.js
+++ b/tests/baselines/reference/inheritSameNamePrivatePropertiesFromSameOrigin.js
@@ -24,14 +24,14 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(B));
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(B));
diff --git a/tests/baselines/reference/inheritance.js b/tests/baselines/reference/inheritance.js
index cbfef2d3382..d5cb8a76360 100644
--- a/tests/baselines/reference/inheritance.js
+++ b/tests/baselines/reference/inheritance.js
@@ -53,14 +53,14 @@ var B2 = (function () {
 var D1 = (function (_super) {
     __extends(D1, _super);
     function D1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D1;
 }(B1));
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(B2));
@@ -72,7 +72,7 @@ var N = (function () {
 var ND = (function (_super) {
     __extends(ND, _super);
     function ND() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ND;
 }(N));
@@ -86,7 +86,7 @@ var Good = (function () {
 var Baad = (function (_super) {
     __extends(Baad, _super);
     function Baad() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Baad.prototype.f = function () { return 0; };
     Baad.prototype.g = function (n) { return 0; };
diff --git a/tests/baselines/reference/inheritance1.js b/tests/baselines/reference/inheritance1.js
index 86de0b76350..8603ce3d22b 100644
--- a/tests/baselines/reference/inheritance1.js
+++ b/tests/baselines/reference/inheritance1.js
@@ -75,7 +75,7 @@ var Control = (function () {
 var Button = (function (_super) {
     __extends(Button, _super);
     function Button() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Button.prototype.select = function () { };
     return Button;
@@ -83,7 +83,7 @@ var Button = (function (_super) {
 var TextBox = (function (_super) {
     __extends(TextBox, _super);
     function TextBox() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     TextBox.prototype.select = function () { };
     return TextBox;
@@ -91,14 +91,14 @@ var TextBox = (function (_super) {
 var ImageBase = (function (_super) {
     __extends(ImageBase, _super);
     function ImageBase() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ImageBase;
 }(Control));
 var Image1 = (function (_super) {
     __extends(Image1, _super);
     function Image1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Image1;
 }(Control));
diff --git a/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollision.js b/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollision.js
index 57a9c897583..8ba41b2d554 100644
--- a/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollision.js
+++ b/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollision.js
@@ -25,14 +25,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.myMethod = function () { };
     return C;
diff --git a/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollisionWithPublicMember.js b/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollisionWithPublicMember.js
index 83c5aa3e4cd..eb70b58a27a 100644
--- a/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollisionWithPublicMember.js
+++ b/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollisionWithPublicMember.js
@@ -25,14 +25,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.myMethod = function () { };
     return C;
diff --git a/tests/baselines/reference/inheritanceGrandParentPublicMemberCollisionWithPrivateMember.js b/tests/baselines/reference/inheritanceGrandParentPublicMemberCollisionWithPrivateMember.js
index b11b6e318a7..8481a883b4b 100644
--- a/tests/baselines/reference/inheritanceGrandParentPublicMemberCollisionWithPrivateMember.js
+++ b/tests/baselines/reference/inheritanceGrandParentPublicMemberCollisionWithPrivateMember.js
@@ -25,14 +25,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.myMethod = function () { };
     return C;
diff --git a/tests/baselines/reference/inheritanceMemberAccessorOverridingAccessor.js b/tests/baselines/reference/inheritanceMemberAccessorOverridingAccessor.js
index 09ea08899d9..6854ec0257c 100644
--- a/tests/baselines/reference/inheritanceMemberAccessorOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceMemberAccessorOverridingAccessor.js
@@ -40,7 +40,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(b.prototype, "x", {
         get: function () {
diff --git a/tests/baselines/reference/inheritanceMemberAccessorOverridingMethod.js b/tests/baselines/reference/inheritanceMemberAccessorOverridingMethod.js
index 59d2abdaab2..92c4902867f 100644
--- a/tests/baselines/reference/inheritanceMemberAccessorOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceMemberAccessorOverridingMethod.js
@@ -31,7 +31,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(b.prototype, "x", {
         get: function () {
diff --git a/tests/baselines/reference/inheritanceMemberAccessorOverridingProperty.js b/tests/baselines/reference/inheritanceMemberAccessorOverridingProperty.js
index 98a95747a8e..b1c716d6347 100644
--- a/tests/baselines/reference/inheritanceMemberAccessorOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceMemberAccessorOverridingProperty.js
@@ -26,7 +26,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(b.prototype, "x", {
         get: function () {
diff --git a/tests/baselines/reference/inheritanceMemberFuncOverridingAccessor.js b/tests/baselines/reference/inheritanceMemberFuncOverridingAccessor.js
index 0d54e5d42fa..f265f2b2223 100644
--- a/tests/baselines/reference/inheritanceMemberFuncOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceMemberFuncOverridingAccessor.js
@@ -37,7 +37,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.prototype.x = function () {
         return "20";
diff --git a/tests/baselines/reference/inheritanceMemberFuncOverridingMethod.js b/tests/baselines/reference/inheritanceMemberFuncOverridingMethod.js
index 9af25c6fdb8..86af837a369 100644
--- a/tests/baselines/reference/inheritanceMemberFuncOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceMemberFuncOverridingMethod.js
@@ -28,7 +28,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.prototype.x = function () {
         return "20";
diff --git a/tests/baselines/reference/inheritanceMemberFuncOverridingProperty.js b/tests/baselines/reference/inheritanceMemberFuncOverridingProperty.js
index 5c77ce08101..62206375b0d 100644
--- a/tests/baselines/reference/inheritanceMemberFuncOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceMemberFuncOverridingProperty.js
@@ -23,7 +23,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.prototype.x = function () {
         return "20";
diff --git a/tests/baselines/reference/inheritanceMemberPropertyOverridingAccessor.js b/tests/baselines/reference/inheritanceMemberPropertyOverridingAccessor.js
index 82c7a94d17c..7b3b30751cb 100644
--- a/tests/baselines/reference/inheritanceMemberPropertyOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceMemberPropertyOverridingAccessor.js
@@ -37,7 +37,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/inheritanceMemberPropertyOverridingMethod.js b/tests/baselines/reference/inheritanceMemberPropertyOverridingMethod.js
index e6929218e63..52f7433ebee 100644
--- a/tests/baselines/reference/inheritanceMemberPropertyOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceMemberPropertyOverridingMethod.js
@@ -26,7 +26,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/inheritanceMemberPropertyOverridingProperty.js b/tests/baselines/reference/inheritanceMemberPropertyOverridingProperty.js
index 85764cddc52..8792716aabd 100644
--- a/tests/baselines/reference/inheritanceMemberPropertyOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceMemberPropertyOverridingProperty.js
@@ -21,7 +21,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/inheritanceOfGenericConstructorMethod1.js b/tests/baselines/reference/inheritanceOfGenericConstructorMethod1.js
index 28fe8144509..aa42fd5f844 100644
--- a/tests/baselines/reference/inheritanceOfGenericConstructorMethod1.js
+++ b/tests/baselines/reference/inheritanceOfGenericConstructorMethod1.js
@@ -21,7 +21,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/inheritanceOfGenericConstructorMethod2.js b/tests/baselines/reference/inheritanceOfGenericConstructorMethod2.js
index 0cc71e168f4..0c91947b3ae 100644
--- a/tests/baselines/reference/inheritanceOfGenericConstructorMethod2.js
+++ b/tests/baselines/reference/inheritanceOfGenericConstructorMethod2.js
@@ -40,7 +40,7 @@ var N;
     var D1 = (function (_super) {
         __extends(D1, _super);
         function D1() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D1;
     }(M.C1));
@@ -48,7 +48,7 @@ var N;
     var D2 = (function (_super) {
         __extends(D2, _super);
         function D2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D2;
     }(M.C2));
diff --git a/tests/baselines/reference/inheritanceStaticAccessorOverridingAccessor.js b/tests/baselines/reference/inheritanceStaticAccessorOverridingAccessor.js
index bb91ee5f9ea..9ccf523cf17 100644
--- a/tests/baselines/reference/inheritanceStaticAccessorOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceStaticAccessorOverridingAccessor.js
@@ -40,7 +40,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(b, "x", {
         get: function () {
diff --git a/tests/baselines/reference/inheritanceStaticAccessorOverridingMethod.js b/tests/baselines/reference/inheritanceStaticAccessorOverridingMethod.js
index 363852a84bf..e454e70741c 100644
--- a/tests/baselines/reference/inheritanceStaticAccessorOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceStaticAccessorOverridingMethod.js
@@ -31,7 +31,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(b, "x", {
         get: function () {
diff --git a/tests/baselines/reference/inheritanceStaticAccessorOverridingProperty.js b/tests/baselines/reference/inheritanceStaticAccessorOverridingProperty.js
index ba8df7a5f0b..867ac6defe7 100644
--- a/tests/baselines/reference/inheritanceStaticAccessorOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceStaticAccessorOverridingProperty.js
@@ -26,7 +26,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(b, "x", {
         get: function () {
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingAccessor.js b/tests/baselines/reference/inheritanceStaticFuncOverridingAccessor.js
index e464029fba5..d7c925a8f94 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingAccessor.js
@@ -37,7 +37,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.x = function () {
         return "20";
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingAccessorOfFuncType.js b/tests/baselines/reference/inheritanceStaticFuncOverridingAccessorOfFuncType.js
index cc825cfa9b5..882df0cd929 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingAccessorOfFuncType.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingAccessorOfFuncType.js
@@ -32,7 +32,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.x = function () {
         return "20";
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingMethod.js b/tests/baselines/reference/inheritanceStaticFuncOverridingMethod.js
index 466c65fa7d5..1f2e7028cfa 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingMethod.js
@@ -28,7 +28,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.x = function () {
         return "20";
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingProperty.js b/tests/baselines/reference/inheritanceStaticFuncOverridingProperty.js
index dfc0ce2c13f..fb993e9240f 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingProperty.js
@@ -23,7 +23,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.x = function () {
         return "20";
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingPropertyOfFuncType.js b/tests/baselines/reference/inheritanceStaticFuncOverridingPropertyOfFuncType.js
index da7850f2071..103bb0048bb 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingPropertyOfFuncType.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingPropertyOfFuncType.js
@@ -23,7 +23,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.x = function () {
         return "20";
diff --git a/tests/baselines/reference/inheritanceStaticFunctionOverridingInstanceProperty.js b/tests/baselines/reference/inheritanceStaticFunctionOverridingInstanceProperty.js
index d5916a9d452..3f6b7a7f3f6 100644
--- a/tests/baselines/reference/inheritanceStaticFunctionOverridingInstanceProperty.js
+++ b/tests/baselines/reference/inheritanceStaticFunctionOverridingInstanceProperty.js
@@ -23,7 +23,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     b.x = function () {
         return new b().x;
diff --git a/tests/baselines/reference/inheritanceStaticMembersCompatible.js b/tests/baselines/reference/inheritanceStaticMembersCompatible.js
index b4cae99b64b..aa68a8a06d7 100644
--- a/tests/baselines/reference/inheritanceStaticMembersCompatible.js
+++ b/tests/baselines/reference/inheritanceStaticMembersCompatible.js
@@ -21,7 +21,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/inheritanceStaticMembersIncompatible.js b/tests/baselines/reference/inheritanceStaticMembersIncompatible.js
index 38c637dd8d1..a4f0b4a7313 100644
--- a/tests/baselines/reference/inheritanceStaticMembersIncompatible.js
+++ b/tests/baselines/reference/inheritanceStaticMembersIncompatible.js
@@ -21,7 +21,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/inheritanceStaticPropertyOverridingAccessor.js b/tests/baselines/reference/inheritanceStaticPropertyOverridingAccessor.js
index 49dc86fc500..ec698d903d4 100644
--- a/tests/baselines/reference/inheritanceStaticPropertyOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceStaticPropertyOverridingAccessor.js
@@ -36,7 +36,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/inheritanceStaticPropertyOverridingMethod.js b/tests/baselines/reference/inheritanceStaticPropertyOverridingMethod.js
index bcd63537540..9c443a94f5d 100644
--- a/tests/baselines/reference/inheritanceStaticPropertyOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceStaticPropertyOverridingMethod.js
@@ -26,7 +26,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/inheritanceStaticPropertyOverridingProperty.js b/tests/baselines/reference/inheritanceStaticPropertyOverridingProperty.js
index c1bdd9b66a2..17e97d0dcb3 100644
--- a/tests/baselines/reference/inheritanceStaticPropertyOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceStaticPropertyOverridingProperty.js
@@ -21,7 +21,7 @@ var a = (function () {
 var b = (function (_super) {
     __extends(b, _super);
     function b() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return b;
 }(a));
diff --git a/tests/baselines/reference/inheritedConstructorWithRestParams.js b/tests/baselines/reference/inheritedConstructorWithRestParams.js
index 6a30836d728..5981c44c2e3 100644
--- a/tests/baselines/reference/inheritedConstructorWithRestParams.js
+++ b/tests/baselines/reference/inheritedConstructorWithRestParams.js
@@ -32,7 +32,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/inheritedConstructorWithRestParams2.js b/tests/baselines/reference/inheritedConstructorWithRestParams2.js
index 9a1b13a8434..249b6447858 100644
--- a/tests/baselines/reference/inheritedConstructorWithRestParams2.js
+++ b/tests/baselines/reference/inheritedConstructorWithRestParams2.js
@@ -53,14 +53,14 @@ var BaseBase2 = (function () {
 var Base = (function (_super) {
     __extends(Base, _super);
     function Base() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Base;
 }(BaseBase));
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/inheritedModuleMembersForClodule.js b/tests/baselines/reference/inheritedModuleMembersForClodule.js
index cd49009fed9..195e4676165 100644
--- a/tests/baselines/reference/inheritedModuleMembersForClodule.js
+++ b/tests/baselines/reference/inheritedModuleMembersForClodule.js
@@ -38,7 +38,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
@@ -52,7 +52,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.bar = function () {
         return this.foo();
diff --git a/tests/baselines/reference/instanceOfAssignability.js b/tests/baselines/reference/instanceOfAssignability.js
index b8f39c5b0e2..31f72babc30 100644
--- a/tests/baselines/reference/instanceOfAssignability.js
+++ b/tests/baselines/reference/instanceOfAssignability.js
@@ -115,14 +115,14 @@ var Animal = (function () {
 var Mammal = (function (_super) {
     __extends(Mammal, _super);
     function Mammal() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Mammal;
 }(Animal));
 var Giraffe = (function (_super) {
     __extends(Giraffe, _super);
     function Giraffe() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Giraffe;
 }(Mammal));
diff --git a/tests/baselines/reference/instancePropertiesInheritedIntoClassType.js b/tests/baselines/reference/instancePropertiesInheritedIntoClassType.js
index 8dc5227685f..c35d089ca90 100644
--- a/tests/baselines/reference/instancePropertiesInheritedIntoClassType.js
+++ b/tests/baselines/reference/instancePropertiesInheritedIntoClassType.js
@@ -69,7 +69,7 @@ var NonGeneric;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(C));
@@ -101,7 +101,7 @@ var Generic;
     var D = (function (_super) {
         __extends(D, _super);
         function D() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D;
     }(C));
diff --git a/tests/baselines/reference/instanceSubtypeCheck2.js b/tests/baselines/reference/instanceSubtypeCheck2.js
index 914f3796001..89dce0056ff 100644
--- a/tests/baselines/reference/instanceSubtypeCheck2.js
+++ b/tests/baselines/reference/instanceSubtypeCheck2.js
@@ -21,7 +21,7 @@ var C1 = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(C1));
diff --git a/tests/baselines/reference/instanceofWithStructurallyIdenticalTypes.js b/tests/baselines/reference/instanceofWithStructurallyIdenticalTypes.js
index 54a574238e5..5e4cd56ea92 100644
--- a/tests/baselines/reference/instanceofWithStructurallyIdenticalTypes.js
+++ b/tests/baselines/reference/instanceofWithStructurallyIdenticalTypes.js
@@ -128,7 +128,7 @@ var A = (function () {
 var A1 = (function (_super) {
     __extends(A1, _super);
     function A1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A1;
 }(A));
@@ -140,7 +140,7 @@ var A2 = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/instantiatedReturnTypeContravariance.js b/tests/baselines/reference/instantiatedReturnTypeContravariance.js
index bc496a63632..f74b8375b19 100644
--- a/tests/baselines/reference/instantiatedReturnTypeContravariance.js
+++ b/tests/baselines/reference/instantiatedReturnTypeContravariance.js
@@ -47,7 +47,7 @@ var c = (function () {
 var d = (function (_super) {
     __extends(d, _super);
     function d() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     d.prototype.foo = function () {
         return null;
diff --git a/tests/baselines/reference/interfaceClassMerging.js b/tests/baselines/reference/interfaceClassMerging.js
index 6542376a19b..f7aebec3856 100644
--- a/tests/baselines/reference/interfaceClassMerging.js
+++ b/tests/baselines/reference/interfaceClassMerging.js
@@ -57,7 +57,7 @@ var Foo = (function () {
 var Bar = (function (_super) {
     __extends(Bar, _super);
     function Bar() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Bar.prototype.method = function (a) {
         return this.optionalProperty;
diff --git a/tests/baselines/reference/interfaceClassMerging2.js b/tests/baselines/reference/interfaceClassMerging2.js
index 70a62da4131..648853ce488 100644
--- a/tests/baselines/reference/interfaceClassMerging2.js
+++ b/tests/baselines/reference/interfaceClassMerging2.js
@@ -53,7 +53,7 @@ var Foo = (function () {
 var Bar = (function (_super) {
     __extends(Bar, _super);
     function Bar() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Bar.prototype.classBarMethod = function () {
         return this;
diff --git a/tests/baselines/reference/interfaceExtendsClass1.js b/tests/baselines/reference/interfaceExtendsClass1.js
index 8324a001f91..1f65014d27d 100644
--- a/tests/baselines/reference/interfaceExtendsClass1.js
+++ b/tests/baselines/reference/interfaceExtendsClass1.js
@@ -32,7 +32,7 @@ var Control = (function () {
 var Button = (function (_super) {
     __extends(Button, _super);
     function Button() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Button.prototype.select = function () { };
     return Button;
@@ -40,7 +40,7 @@ var Button = (function (_super) {
 var TextBox = (function (_super) {
     __extends(TextBox, _super);
     function TextBox() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     TextBox.prototype.select = function () { };
     return TextBox;
@@ -48,7 +48,7 @@ var TextBox = (function (_super) {
 var Image = (function (_super) {
     __extends(Image, _super);
     function Image() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Image;
 }(Control));
diff --git a/tests/baselines/reference/interfaceExtendsClassWithPrivate1.js b/tests/baselines/reference/interfaceExtendsClassWithPrivate1.js
index 1179ff101df..5bbe6a09d48 100644
--- a/tests/baselines/reference/interfaceExtendsClassWithPrivate1.js
+++ b/tests/baselines/reference/interfaceExtendsClassWithPrivate1.js
@@ -43,7 +43,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.foo = function (x) { return x; };
     D.prototype.other = function (x) { return x; };
diff --git a/tests/baselines/reference/interfaceExtendsClassWithPrivate2.js b/tests/baselines/reference/interfaceExtendsClassWithPrivate2.js
index 49b5efbd012..627f1e2ea9a 100644
--- a/tests/baselines/reference/interfaceExtendsClassWithPrivate2.js
+++ b/tests/baselines/reference/interfaceExtendsClassWithPrivate2.js
@@ -39,7 +39,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = 2;
         _this.y = 3;
         return _this;
@@ -52,7 +52,7 @@ var D = (function (_super) {
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = "";
         return _this;
     }
diff --git a/tests/baselines/reference/interfaceImplementation8.js b/tests/baselines/reference/interfaceImplementation8.js
index afb5a795264..43ce713f07d 100644
--- a/tests/baselines/reference/interfaceImplementation8.js
+++ b/tests/baselines/reference/interfaceImplementation8.js
@@ -64,21 +64,21 @@ var C3 = (function () {
 var C4 = (function (_super) {
     __extends(C4, _super);
     function C4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C4;
 }(C1));
 var C5 = (function (_super) {
     __extends(C5, _super);
     function C5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C5;
 }(C2));
 var C6 = (function (_super) {
     __extends(C6, _super);
     function C6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C6;
 }(C3));
@@ -90,7 +90,7 @@ var C7 = (function () {
 var C8 = (function (_super) {
     __extends(C8, _super);
     function C8() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C8;
 }(C7));
diff --git a/tests/baselines/reference/invalidModuleWithStatementsOfEveryKind.js b/tests/baselines/reference/invalidModuleWithStatementsOfEveryKind.js
index 6e9b09c906f..20f029afd4a 100644
--- a/tests/baselines/reference/invalidModuleWithStatementsOfEveryKind.js
+++ b/tests/baselines/reference/invalidModuleWithStatementsOfEveryKind.js
@@ -95,7 +95,7 @@ var Y;
     var BB = (function (_super) {
         __extends(BB, _super);
         function BB() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return BB;
     }(A));
@@ -110,7 +110,7 @@ var Y2;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(AA));
@@ -144,7 +144,7 @@ var YY;
     var BB = (function (_super) {
         __extends(BB, _super);
         function BB() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return BB;
     }(A));
@@ -159,7 +159,7 @@ var YY2;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(AA));
@@ -193,7 +193,7 @@ var YYY;
     var BB = (function (_super) {
         __extends(BB, _super);
         function BB() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return BB;
     }(A));
@@ -208,7 +208,7 @@ var YYY2;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(AA));
diff --git a/tests/baselines/reference/invalidMultipleVariableDeclarations.js b/tests/baselines/reference/invalidMultipleVariableDeclarations.js
index 340429cc398..105882b8e23 100644
--- a/tests/baselines/reference/invalidMultipleVariableDeclarations.js
+++ b/tests/baselines/reference/invalidMultipleVariableDeclarations.js
@@ -67,7 +67,7 @@ var C = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(C));
diff --git a/tests/baselines/reference/invalidReturnStatements.js b/tests/baselines/reference/invalidReturnStatements.js
index a6b07b7d7bd..7a528745b1d 100644
--- a/tests/baselines/reference/invalidReturnStatements.js
+++ b/tests/baselines/reference/invalidReturnStatements.js
@@ -41,7 +41,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/isolatedModulesImportExportElision.js b/tests/baselines/reference/isolatedModulesImportExportElision.js
index 6f1d38dcbb5..d00c7f1f0dc 100644
--- a/tests/baselines/reference/isolatedModulesImportExportElision.js
+++ b/tests/baselines/reference/isolatedModulesImportExportElision.js
@@ -26,7 +26,7 @@ var ns = require("module");
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(module_2.c2.C));
diff --git a/tests/baselines/reference/jsxInExtendsClause.js b/tests/baselines/reference/jsxInExtendsClause.js
index 8204067cb04..2ae0fb98d45 100644
--- a/tests/baselines/reference/jsxInExtendsClause.js
+++ b/tests/baselines/reference/jsxInExtendsClause.js
@@ -20,13 +20,13 @@ var __extends = (this && this.__extends) || function (d, b) {
 var Foo = (function (_super) {
     __extends(Foo, _super);
     function Foo() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Foo;
 }(createComponentClass(function () { return (function (_super) {
     __extends(class_1, _super);
     function class_1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     class_1.prototype.render = function () {
         return React.createElement("span", null, "Hello, world!");
diff --git a/tests/baselines/reference/jsxViaImport.2.js b/tests/baselines/reference/jsxViaImport.2.js
index 19432238e0b..97852a3ce38 100644
--- a/tests/baselines/reference/jsxViaImport.2.js
+++ b/tests/baselines/reference/jsxViaImport.2.js
@@ -35,7 +35,7 @@ var BaseComponent_1 = require("BaseComponent");
 var TestComponent = (function (_super) {
     __extends(TestComponent, _super);
     function TestComponent() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     TestComponent.prototype.render = function () {
         return <BaseComponent_1.default />;
diff --git a/tests/baselines/reference/jsxViaImport.js b/tests/baselines/reference/jsxViaImport.js
index 604787af744..80ec0a3ae01 100644
--- a/tests/baselines/reference/jsxViaImport.js
+++ b/tests/baselines/reference/jsxViaImport.js
@@ -35,7 +35,7 @@ var BaseComponent = require("BaseComponent");
 var TestComponent = (function (_super) {
     __extends(TestComponent, _super);
     function TestComponent() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     TestComponent.prototype.render = function () {
         return <BaseComponent />;
diff --git a/tests/baselines/reference/keyofAndIndexedAccess.js b/tests/baselines/reference/keyofAndIndexedAccess.js
index 4b93897fdc4..3e430016032 100644
--- a/tests/baselines/reference/keyofAndIndexedAccess.js
+++ b/tests/baselines/reference/keyofAndIndexedAccess.js
@@ -445,7 +445,7 @@ var Shape = (function () {
 var TaggedShape = (function (_super) {
     __extends(TaggedShape, _super);
     function TaggedShape() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return TaggedShape;
 }(Shape));
diff --git a/tests/baselines/reference/lambdaArgCrash.js b/tests/baselines/reference/lambdaArgCrash.js
index 47db7f3ce64..a01ae6168e4 100644
--- a/tests/baselines/reference/lambdaArgCrash.js
+++ b/tests/baselines/reference/lambdaArgCrash.js
@@ -56,7 +56,7 @@ var Event = (function () {
 var ItemSetEvent = (function (_super) {
     __extends(ItemSetEvent, _super);
     function ItemSetEvent() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     ItemSetEvent.prototype.add = function (listener) {
         _super.prototype.add.call(this, listener);
diff --git a/tests/baselines/reference/localTypes1.js b/tests/baselines/reference/localTypes1.js
index 100452b7a96..b58e3f63a76 100644
--- a/tests/baselines/reference/localTypes1.js
+++ b/tests/baselines/reference/localTypes1.js
@@ -300,7 +300,7 @@ function f6() {
         var B = (function (_super) {
             __extends(B, _super);
             function B() {
-                return _super.apply(this, arguments) || this;
+                return _super !== null && _super.apply(this, arguments) || this;
             }
             return B;
         }(A));
@@ -308,7 +308,7 @@ function f6() {
             var C = (function (_super) {
                 __extends(C, _super);
                 function C() {
-                    return _super.apply(this, arguments) || this;
+                    return _super !== null && _super.apply(this, arguments) || this;
                 }
                 return C;
             }(B));
diff --git a/tests/baselines/reference/m7Bugs.js b/tests/baselines/reference/m7Bugs.js
index e5a4d11f00c..35a2551ad66 100644
--- a/tests/baselines/reference/m7Bugs.js
+++ b/tests/baselines/reference/m7Bugs.js
@@ -42,7 +42,7 @@ var C1 = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(C1));
diff --git a/tests/baselines/reference/mergedDeclarations5.js b/tests/baselines/reference/mergedDeclarations5.js
index b24e86eca58..92f679fcb7f 100644
--- a/tests/baselines/reference/mergedDeclarations5.js
+++ b/tests/baselines/reference/mergedDeclarations5.js
@@ -27,7 +27,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.foo = function () { };
     return B;
diff --git a/tests/baselines/reference/mergedDeclarations6.js b/tests/baselines/reference/mergedDeclarations6.js
index d610e4ab46f..1c1be96e23e 100644
--- a/tests/baselines/reference/mergedDeclarations6.js
+++ b/tests/baselines/reference/mergedDeclarations6.js
@@ -47,7 +47,7 @@ define(["require", "exports", "./a"], function (require, exports, a_1) {
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         B.prototype.setProtected = function () {
         };
diff --git a/tests/baselines/reference/mergedInheritedClassInterface.js b/tests/baselines/reference/mergedInheritedClassInterface.js
index 0f598f2cf78..3e4448c998b 100644
--- a/tests/baselines/reference/mergedInheritedClassInterface.js
+++ b/tests/baselines/reference/mergedInheritedClassInterface.js
@@ -61,7 +61,7 @@ var BaseClass = (function () {
 var Child = (function (_super) {
     __extends(Child, _super);
     function Child() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Child.prototype.method = function () { };
     return Child;
@@ -75,7 +75,7 @@ var ChildNoBaseClass = (function () {
 var Grandchild = (function (_super) {
     __extends(Grandchild, _super);
     function Grandchild() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Grandchild;
 }(ChildNoBaseClass));
diff --git a/tests/baselines/reference/mergedInterfacesWithInheritedPrivates2.js b/tests/baselines/reference/mergedInterfacesWithInheritedPrivates2.js
index 6dccf1dfdd9..5738ded2461 100644
--- a/tests/baselines/reference/mergedInterfacesWithInheritedPrivates2.js
+++ b/tests/baselines/reference/mergedInterfacesWithInheritedPrivates2.js
@@ -50,14 +50,14 @@ var C2 = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E;
 }(C2));
diff --git a/tests/baselines/reference/mergedInterfacesWithInheritedPrivates3.js b/tests/baselines/reference/mergedInterfacesWithInheritedPrivates3.js
index a3ca796575c..b6075756d47 100644
--- a/tests/baselines/reference/mergedInterfacesWithInheritedPrivates3.js
+++ b/tests/baselines/reference/mergedInterfacesWithInheritedPrivates3.js
@@ -57,7 +57,7 @@ var C2 = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/moduleAsBaseType.js b/tests/baselines/reference/moduleAsBaseType.js
index fc0533a2470..78b4dbdf6f8 100644
--- a/tests/baselines/reference/moduleAsBaseType.js
+++ b/tests/baselines/reference/moduleAsBaseType.js
@@ -13,7 +13,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(M));
diff --git a/tests/baselines/reference/moduleImportedForTypeArgumentPosition.js b/tests/baselines/reference/moduleImportedForTypeArgumentPosition.js
index 51d9eb89b1d..6fa1bbe91c4 100644
--- a/tests/baselines/reference/moduleImportedForTypeArgumentPosition.js
+++ b/tests/baselines/reference/moduleImportedForTypeArgumentPosition.js
@@ -31,7 +31,7 @@ define(["require", "exports"], function (require, exports) {
     var Test1 = (function (_super) {
         __extends(Test1, _super);
         function Test1() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Test1;
     }(C1));
diff --git a/tests/baselines/reference/moduleWithStatementsOfEveryKind.js b/tests/baselines/reference/moduleWithStatementsOfEveryKind.js
index 4243c9849cf..45331425188 100644
--- a/tests/baselines/reference/moduleWithStatementsOfEveryKind.js
+++ b/tests/baselines/reference/moduleWithStatementsOfEveryKind.js
@@ -79,14 +79,14 @@ var A;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(AA));
     var BB = (function (_super) {
         __extends(BB, _super);
         function BB() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return BB;
     }(A));
@@ -130,7 +130,7 @@ var Y;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(AA));
@@ -138,7 +138,7 @@ var Y;
     var BB = (function (_super) {
         __extends(BB, _super);
         function BB() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return BB;
     }(A));
diff --git a/tests/baselines/reference/multipleInheritance.js b/tests/baselines/reference/multipleInheritance.js
index 9c0e865cdb7..b35c7d21bab 100644
--- a/tests/baselines/reference/multipleInheritance.js
+++ b/tests/baselines/reference/multipleInheritance.js
@@ -57,28 +57,28 @@ var B2 = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(B1));
 var D1 = (function (_super) {
     __extends(D1, _super);
     function D1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D1;
 }(B1));
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(B2));
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E;
 }(D1));
@@ -90,7 +90,7 @@ var N = (function () {
 var ND = (function (_super) {
     __extends(ND, _super);
     function ND() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ND;
 }(N));
@@ -104,7 +104,7 @@ var Good = (function () {
 var Baad = (function (_super) {
     __extends(Baad, _super);
     function Baad() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Baad.prototype.f = function () { return 0; };
     Baad.prototype.g = function (n) { return 0; };
diff --git a/tests/baselines/reference/mutuallyRecursiveGenericBaseTypes2.js b/tests/baselines/reference/mutuallyRecursiveGenericBaseTypes2.js
index 8b59564d465..0f35f3fb55b 100644
--- a/tests/baselines/reference/mutuallyRecursiveGenericBaseTypes2.js
+++ b/tests/baselines/reference/mutuallyRecursiveGenericBaseTypes2.js
@@ -25,7 +25,7 @@ var foo = (function () {
 var foo2 = (function (_super) {
     __extends(foo2, _super);
     function foo2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return foo2;
 }(foo));
diff --git a/tests/baselines/reference/noEmitHelpers.js b/tests/baselines/reference/noEmitHelpers.js
index fdb7cbab7d4..1a9ad2579b9 100644
--- a/tests/baselines/reference/noEmitHelpers.js
+++ b/tests/baselines/reference/noEmitHelpers.js
@@ -13,7 +13,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/noImplicitAnyMissingGetAccessor.js b/tests/baselines/reference/noImplicitAnyMissingGetAccessor.js
index cc4c9422373..bde4958f647 100644
--- a/tests/baselines/reference/noImplicitAnyMissingGetAccessor.js
+++ b/tests/baselines/reference/noImplicitAnyMissingGetAccessor.js
@@ -26,7 +26,7 @@ var Parent = (function () {
 var Child = (function (_super) {
     __extends(Child, _super);
     function Child() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(Child.prototype, "message", {
         set: function (str) {
diff --git a/tests/baselines/reference/noImplicitAnyMissingSetAccessor.js b/tests/baselines/reference/noImplicitAnyMissingSetAccessor.js
index 1323955c05e..efe81c88d9f 100644
--- a/tests/baselines/reference/noImplicitAnyMissingSetAccessor.js
+++ b/tests/baselines/reference/noImplicitAnyMissingSetAccessor.js
@@ -25,7 +25,7 @@ var Parent = (function () {
 var Child = (function (_super) {
     __extends(Child, _super);
     function Child() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(Child.prototype, "message", {
         get: function () {
diff --git a/tests/baselines/reference/nonGenericClassExtendingGenericClassWithAny.js b/tests/baselines/reference/nonGenericClassExtendingGenericClassWithAny.js
index b0a3365193d..f28e57c0d71 100644
--- a/tests/baselines/reference/nonGenericClassExtendingGenericClassWithAny.js
+++ b/tests/baselines/reference/nonGenericClassExtendingGenericClassWithAny.js
@@ -19,7 +19,7 @@ var Foo = (function () {
 var Bar = (function (_super) {
     __extends(Bar, _super);
     function Bar() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Bar;
 }(Foo)); // Valid
diff --git a/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.js b/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.js
index 92c8b380e00..a67b03dee8e 100644
--- a/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.js
+++ b/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.js
@@ -61,7 +61,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.bar = function () { return ''; };
     return B;
diff --git a/tests/baselines/reference/numericIndexerConstraint3.js b/tests/baselines/reference/numericIndexerConstraint3.js
index 29cb75b4234..9f764b6b378 100644
--- a/tests/baselines/reference/numericIndexerConstraint3.js
+++ b/tests/baselines/reference/numericIndexerConstraint3.js
@@ -26,7 +26,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/numericIndexerConstraint4.js b/tests/baselines/reference/numericIndexerConstraint4.js
index 135e169c4a9..5e4dcfd1d88 100644
--- a/tests/baselines/reference/numericIndexerConstraint4.js
+++ b/tests/baselines/reference/numericIndexerConstraint4.js
@@ -26,7 +26,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/numericIndexerTyping2.js b/tests/baselines/reference/numericIndexerTyping2.js
index 5b9e797bdec..a336eb6022f 100644
--- a/tests/baselines/reference/numericIndexerTyping2.js
+++ b/tests/baselines/reference/numericIndexerTyping2.js
@@ -26,7 +26,7 @@ var I = (function () {
 var I2 = (function (_super) {
     __extends(I2, _super);
     function I2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return I2;
 }(I));
diff --git a/tests/baselines/reference/objectTypeHidingMembersOfExtendedObject.js b/tests/baselines/reference/objectTypeHidingMembersOfExtendedObject.js
index 17045d65af0..e577cecca17 100644
--- a/tests/baselines/reference/objectTypeHidingMembersOfExtendedObject.js
+++ b/tests/baselines/reference/objectTypeHidingMembersOfExtendedObject.js
@@ -68,7 +68,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.js b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.js
index e82cef9bdd6..c502906fa50 100644
--- a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.js
+++ b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.js
@@ -147,14 +147,14 @@ var C = (function () {
 var PA = (function (_super) {
     __extends(PA, _super);
     function PA() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PA;
 }(A));
 var PB = (function (_super) {
     __extends(PB, _super);
     function PB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PB;
 }(B));
diff --git a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.js b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.js
index abcea113670..5e050c57cbb 100644
--- a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.js
+++ b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.js
@@ -140,7 +140,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -162,14 +162,14 @@ var C = (function () {
 var PA = (function (_super) {
     __extends(PA, _super);
     function PA() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PA;
 }(A));
 var PB = (function (_super) {
     __extends(PB, _super);
     function PB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PB;
 }(B));
diff --git a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.js b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.js
index f5aeb177472..52ab0f5f2b7 100644
--- a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.js
+++ b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.js
@@ -147,14 +147,14 @@ var C = (function () {
 var PA = (function (_super) {
     __extends(PA, _super);
     function PA() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PA;
 }(A));
 var PB = (function (_super) {
     __extends(PB, _super);
     function PB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PB;
 }(B));
diff --git a/tests/baselines/reference/objectTypesIdentityWithPrivates.js b/tests/baselines/reference/objectTypesIdentityWithPrivates.js
index 3946027063f..d0316ad91a9 100644
--- a/tests/baselines/reference/objectTypesIdentityWithPrivates.js
+++ b/tests/baselines/reference/objectTypesIdentityWithPrivates.js
@@ -145,14 +145,14 @@ var C = (function () {
 var PA = (function (_super) {
     __extends(PA, _super);
     function PA() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PA;
 }(A));
 var PB = (function (_super) {
     __extends(PB, _super);
     function PB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PB;
 }(B));
diff --git a/tests/baselines/reference/objectTypesIdentityWithPrivates2.js b/tests/baselines/reference/objectTypesIdentityWithPrivates2.js
index 9cae6960a2e..566f1fea078 100644
--- a/tests/baselines/reference/objectTypesIdentityWithPrivates2.js
+++ b/tests/baselines/reference/objectTypesIdentityWithPrivates2.js
@@ -53,7 +53,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/objectTypesIdentityWithPrivates3.js b/tests/baselines/reference/objectTypesIdentityWithPrivates3.js
index 68754a583aa..b1e07379536 100644
--- a/tests/baselines/reference/objectTypesIdentityWithPrivates3.js
+++ b/tests/baselines/reference/objectTypesIdentityWithPrivates3.js
@@ -39,7 +39,7 @@ var C1 = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(C1));
@@ -53,7 +53,7 @@ var C3 = (function () {
 var C4 = (function (_super) {
     __extends(C4, _super);
     function C4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C4;
 }(C3));
diff --git a/tests/baselines/reference/objectTypesIdentityWithStringIndexers.js b/tests/baselines/reference/objectTypesIdentityWithStringIndexers.js
index b0211bbbba7..ca17ffdb3bd 100644
--- a/tests/baselines/reference/objectTypesIdentityWithStringIndexers.js
+++ b/tests/baselines/reference/objectTypesIdentityWithStringIndexers.js
@@ -147,14 +147,14 @@ var C = (function () {
 var PA = (function (_super) {
     __extends(PA, _super);
     function PA() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PA;
 }(A));
 var PB = (function (_super) {
     __extends(PB, _super);
     function PB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PB;
 }(B));
diff --git a/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.js b/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.js
index 00d7d1e81d8..a1042a03c6b 100644
--- a/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.js
+++ b/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.js
@@ -140,7 +140,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -162,14 +162,14 @@ var C = (function () {
 var PA = (function (_super) {
     __extends(PA, _super);
     function PA() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PA;
 }(A));
 var PB = (function (_super) {
     __extends(PB, _super);
     function PB() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return PB;
 }(B));
diff --git a/tests/baselines/reference/optionalConstructorArgInSuper.js b/tests/baselines/reference/optionalConstructorArgInSuper.js
index e460ab3fb15..75a13f41458 100644
--- a/tests/baselines/reference/optionalConstructorArgInSuper.js
+++ b/tests/baselines/reference/optionalConstructorArgInSuper.js
@@ -25,7 +25,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
diff --git a/tests/baselines/reference/optionalMethods.js b/tests/baselines/reference/optionalMethods.js
index 28ed0bcd76e..853a77f00c1 100644
--- a/tests/baselines/reference/optionalMethods.js
+++ b/tests/baselines/reference/optionalMethods.js
@@ -109,7 +109,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.a = 1;
         return _this;
     }
diff --git a/tests/baselines/reference/optionalParamInOverride.js b/tests/baselines/reference/optionalParamInOverride.js
index 1312a89502a..c17c451ec57 100644
--- a/tests/baselines/reference/optionalParamInOverride.js
+++ b/tests/baselines/reference/optionalParamInOverride.js
@@ -22,7 +22,7 @@ var Z = (function () {
 var Y = (function (_super) {
     __extends(Y, _super);
     function Y() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Y.prototype.func = function (value) { };
     return Y;
diff --git a/tests/baselines/reference/outModuleConcatAmd.js b/tests/baselines/reference/outModuleConcatAmd.js
index 5054c2a3c33..ab778aae771 100644
--- a/tests/baselines/reference/outModuleConcatAmd.js
+++ b/tests/baselines/reference/outModuleConcatAmd.js
@@ -28,7 +28,7 @@ define("b", ["require", "exports", "ref/a"], function (require, exports, a_1) {
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(a_1.A));
diff --git a/tests/baselines/reference/outModuleConcatAmd.sourcemap.txt b/tests/baselines/reference/outModuleConcatAmd.sourcemap.txt
index 34ab74816ad..79e8622529f 100644
--- a/tests/baselines/reference/outModuleConcatAmd.sourcemap.txt
+++ b/tests/baselines/reference/outModuleConcatAmd.sourcemap.txt
@@ -92,11 +92,11 @@ sourceFile:tests/cases/compiler/b.ts
 ---
 >>>        function B() {
 1 >^^^^^^^^
-2 >        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+2 >        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
 1 >Emitted(19, 9) Source(2, 1) + SourceIndex(1)
 ---
->>>            return _super.apply(this, arguments) || this;
+>>>            return _super !== null && _super.apply(this, arguments) || this;
 >>>        }
 1->^^^^^^^^
 2 >        ^
diff --git a/tests/baselines/reference/outModuleConcatSystem.js b/tests/baselines/reference/outModuleConcatSystem.js
index a615090f33a..5651fe47ddf 100644
--- a/tests/baselines/reference/outModuleConcatSystem.js
+++ b/tests/baselines/reference/outModuleConcatSystem.js
@@ -44,7 +44,7 @@ System.register("b", ["ref/a"], function (exports_2, context_2) {
             B = (function (_super) {
                 __extends(B, _super);
                 function B() {
-                    return _super.apply(this, arguments) || this;
+                    return _super !== null && _super.apply(this, arguments) || this;
                 }
                 return B;
             }(a_1.A));
diff --git a/tests/baselines/reference/outModuleConcatSystem.sourcemap.txt b/tests/baselines/reference/outModuleConcatSystem.sourcemap.txt
index 732214237fa..f0f66423932 100644
--- a/tests/baselines/reference/outModuleConcatSystem.sourcemap.txt
+++ b/tests/baselines/reference/outModuleConcatSystem.sourcemap.txt
@@ -109,11 +109,11 @@ sourceFile:tests/cases/compiler/b.ts
 ---
 >>>                function B() {
 1 >^^^^^^^^^^^^^^^^
-2 >                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+2 >                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
 1 >Emitted(35, 17) Source(2, 1) + SourceIndex(1)
 ---
->>>                    return _super.apply(this, arguments) || this;
+>>>                    return _super !== null && _super.apply(this, arguments) || this;
 >>>                }
 1->^^^^^^^^^^^^^^^^
 2 >                ^
diff --git a/tests/baselines/reference/outModuleTripleSlashRefs.js b/tests/baselines/reference/outModuleTripleSlashRefs.js
index b9ff7c15b61..25ef1faf730 100644
--- a/tests/baselines/reference/outModuleTripleSlashRefs.js
+++ b/tests/baselines/reference/outModuleTripleSlashRefs.js
@@ -57,7 +57,7 @@ define("b", ["require", "exports", "ref/a"], function (require, exports, a_1) {
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(a_1.A));
diff --git a/tests/baselines/reference/outModuleTripleSlashRefs.sourcemap.txt b/tests/baselines/reference/outModuleTripleSlashRefs.sourcemap.txt
index ce41bae6de3..dac4465dde9 100644
--- a/tests/baselines/reference/outModuleTripleSlashRefs.sourcemap.txt
+++ b/tests/baselines/reference/outModuleTripleSlashRefs.sourcemap.txt
@@ -166,11 +166,11 @@ sourceFile:tests/cases/compiler/b.ts
 ---
 >>>        function B() {
 1 >^^^^^^^^
-2 >        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+2 >        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
 1 >Emitted(26, 9) Source(2, 1) + SourceIndex(2)
 ---
->>>            return _super.apply(this, arguments) || this;
+>>>            return _super !== null && _super.apply(this, arguments) || this;
 >>>        }
 1->^^^^^^^^
 2 >        ^
diff --git a/tests/baselines/reference/overload1.js b/tests/baselines/reference/overload1.js
index 41aafdfb29c..e214027ccd1 100644
--- a/tests/baselines/reference/overload1.js
+++ b/tests/baselines/reference/overload1.js
@@ -56,7 +56,7 @@ var O;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
@@ -64,7 +64,7 @@ var O;
     var C = (function (_super) {
         __extends(C, _super);
         function C() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return C;
     }(B));
diff --git a/tests/baselines/reference/overloadOnConstConstraintChecks1.js b/tests/baselines/reference/overloadOnConstConstraintChecks1.js
index f9d1c81b06b..d2ab4491f51 100644
--- a/tests/baselines/reference/overloadOnConstConstraintChecks1.js
+++ b/tests/baselines/reference/overloadOnConstConstraintChecks1.js
@@ -37,7 +37,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.prototype.bar = function () { };
     return Derived1;
@@ -45,7 +45,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived2.prototype.baz = function () { };
     return Derived2;
@@ -53,7 +53,7 @@ var Derived2 = (function (_super) {
 var Derived3 = (function (_super) {
     __extends(Derived3, _super);
     function Derived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived3.prototype.biz = function () { };
     return Derived3;
diff --git a/tests/baselines/reference/overloadOnConstConstraintChecks2.js b/tests/baselines/reference/overloadOnConstConstraintChecks2.js
index a680a62ddfe..5359cf3ef62 100644
--- a/tests/baselines/reference/overloadOnConstConstraintChecks2.js
+++ b/tests/baselines/reference/overloadOnConstConstraintChecks2.js
@@ -25,14 +25,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.foo = function () { };
     return C;
diff --git a/tests/baselines/reference/overloadOnConstConstraintChecks3.js b/tests/baselines/reference/overloadOnConstConstraintChecks3.js
index 025e449fd6f..a1a2bdf7df8 100644
--- a/tests/baselines/reference/overloadOnConstConstraintChecks3.js
+++ b/tests/baselines/reference/overloadOnConstConstraintChecks3.js
@@ -27,14 +27,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.foo = function () { };
     return C;
diff --git a/tests/baselines/reference/overloadOnConstConstraintChecks4.js b/tests/baselines/reference/overloadOnConstConstraintChecks4.js
index 0f436a5f0b2..bed2f683c5e 100644
--- a/tests/baselines/reference/overloadOnConstConstraintChecks4.js
+++ b/tests/baselines/reference/overloadOnConstConstraintChecks4.js
@@ -27,7 +27,7 @@ var Z = (function () {
 var A = (function (_super) {
     __extends(A, _super);
     function A() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = 1;
         return _this;
     }
@@ -36,14 +36,14 @@ var A = (function (_super) {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.foo = function () { };
     return C;
diff --git a/tests/baselines/reference/overloadOnConstantsInvalidOverload1.js b/tests/baselines/reference/overloadOnConstantsInvalidOverload1.js
index e3f58c0f7d0..dc8f9bd85bf 100644
--- a/tests/baselines/reference/overloadOnConstantsInvalidOverload1.js
+++ b/tests/baselines/reference/overloadOnConstantsInvalidOverload1.js
@@ -26,7 +26,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.prototype.bar = function () { };
     return Derived1;
@@ -34,7 +34,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived2.prototype.baz = function () { };
     return Derived2;
@@ -42,7 +42,7 @@ var Derived2 = (function (_super) {
 var Derived3 = (function (_super) {
     __extends(Derived3, _super);
     function Derived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived3.prototype.biz = function () { };
     return Derived3;
diff --git a/tests/baselines/reference/overloadResolution.js b/tests/baselines/reference/overloadResolution.js
index e5cc35c39c4..33c995197d1 100644
--- a/tests/baselines/reference/overloadResolution.js
+++ b/tests/baselines/reference/overloadResolution.js
@@ -108,21 +108,21 @@ var SomeBase = (function () {
 var SomeDerived1 = (function (_super) {
     __extends(SomeDerived1, _super);
     function SomeDerived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived1;
 }(SomeBase));
 var SomeDerived2 = (function (_super) {
     __extends(SomeDerived2, _super);
     function SomeDerived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived2;
 }(SomeBase));
 var SomeDerived3 = (function (_super) {
     __extends(SomeDerived3, _super);
     function SomeDerived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived3;
 }(SomeBase));
diff --git a/tests/baselines/reference/overloadResolutionClassConstructors.js b/tests/baselines/reference/overloadResolutionClassConstructors.js
index 7c8b2e2ccb6..c1d4603f1b9 100644
--- a/tests/baselines/reference/overloadResolutionClassConstructors.js
+++ b/tests/baselines/reference/overloadResolutionClassConstructors.js
@@ -115,21 +115,21 @@ var SomeBase = (function () {
 var SomeDerived1 = (function (_super) {
     __extends(SomeDerived1, _super);
     function SomeDerived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived1;
 }(SomeBase));
 var SomeDerived2 = (function (_super) {
     __extends(SomeDerived2, _super);
     function SomeDerived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived2;
 }(SomeBase));
 var SomeDerived3 = (function (_super) {
     __extends(SomeDerived3, _super);
     function SomeDerived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived3;
 }(SomeBase));
diff --git a/tests/baselines/reference/overloadResolutionConstructors.js b/tests/baselines/reference/overloadResolutionConstructors.js
index 44bbfbcec2b..206f7c40b3a 100644
--- a/tests/baselines/reference/overloadResolutionConstructors.js
+++ b/tests/baselines/reference/overloadResolutionConstructors.js
@@ -116,21 +116,21 @@ var SomeBase = (function () {
 var SomeDerived1 = (function (_super) {
     __extends(SomeDerived1, _super);
     function SomeDerived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived1;
 }(SomeBase));
 var SomeDerived2 = (function (_super) {
     __extends(SomeDerived2, _super);
     function SomeDerived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived2;
 }(SomeBase));
 var SomeDerived3 = (function (_super) {
     __extends(SomeDerived3, _super);
     function SomeDerived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived3;
 }(SomeBase));
diff --git a/tests/baselines/reference/overloadingOnConstants1.js b/tests/baselines/reference/overloadingOnConstants1.js
index 96f4f7baf24..ca0a2b44d97 100644
--- a/tests/baselines/reference/overloadingOnConstants1.js
+++ b/tests/baselines/reference/overloadingOnConstants1.js
@@ -40,7 +40,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.prototype.bar = function () { };
     return Derived1;
@@ -48,7 +48,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived2.prototype.baz = function () { };
     return Derived2;
@@ -56,7 +56,7 @@ var Derived2 = (function (_super) {
 var Derived3 = (function (_super) {
     __extends(Derived3, _super);
     function Derived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived3.prototype.biz = function () { };
     return Derived3;
diff --git a/tests/baselines/reference/overloadingOnConstants2.js b/tests/baselines/reference/overloadingOnConstants2.js
index 0c34d0f4b76..1f771fb5ee8 100644
--- a/tests/baselines/reference/overloadingOnConstants2.js
+++ b/tests/baselines/reference/overloadingOnConstants2.js
@@ -42,7 +42,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/overridingPrivateStaticMembers.js b/tests/baselines/reference/overridingPrivateStaticMembers.js
index ca5616450ba..b185bfe1c48 100644
--- a/tests/baselines/reference/overridingPrivateStaticMembers.js
+++ b/tests/baselines/reference/overridingPrivateStaticMembers.js
@@ -21,7 +21,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/parseErrorInHeritageClause1.js b/tests/baselines/reference/parseErrorInHeritageClause1.js
index a9ca0a6db73..50719268aae 100644
--- a/tests/baselines/reference/parseErrorInHeritageClause1.js
+++ b/tests/baselines/reference/parseErrorInHeritageClause1.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/parser509630.js b/tests/baselines/reference/parser509630.js
index d3648dc5b64..91a598a2374 100644
--- a/tests/baselines/reference/parser509630.js
+++ b/tests/baselines/reference/parser509630.js
@@ -21,7 +21,7 @@ var Type = (function () {
 var Any = (function (_super) {
     __extends(Any, _super);
     function Any() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Any;
 }(Type));
diff --git a/tests/baselines/reference/parserAstSpans1.js b/tests/baselines/reference/parserAstSpans1.js
index 6b86353b959..5cccc236601 100644
--- a/tests/baselines/reference/parserAstSpans1.js
+++ b/tests/baselines/reference/parserAstSpans1.js
@@ -363,7 +363,7 @@ c2_i.nc_f1();
 var c4 = (function (_super) {
     __extends(c4, _super);
     function c4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return c4;
 }(c2));
diff --git a/tests/baselines/reference/parserClassDeclaration1.js b/tests/baselines/reference/parserClassDeclaration1.js
index a61b492b7a9..e88065ae6c2 100644
--- a/tests/baselines/reference/parserClassDeclaration1.js
+++ b/tests/baselines/reference/parserClassDeclaration1.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/parserClassDeclaration3.js b/tests/baselines/reference/parserClassDeclaration3.js
index f58f0ab00cb..e13e2e0aba1 100644
--- a/tests/baselines/reference/parserClassDeclaration3.js
+++ b/tests/baselines/reference/parserClassDeclaration3.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(B));
diff --git a/tests/baselines/reference/parserClassDeclaration4.js b/tests/baselines/reference/parserClassDeclaration4.js
index 912aa8c6581..0eb120785d7 100644
--- a/tests/baselines/reference/parserClassDeclaration4.js
+++ b/tests/baselines/reference/parserClassDeclaration4.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/parserClassDeclaration5.js b/tests/baselines/reference/parserClassDeclaration5.js
index 054aaf0eb7a..69e5b4e7d0d 100644
--- a/tests/baselines/reference/parserClassDeclaration5.js
+++ b/tests/baselines/reference/parserClassDeclaration5.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/parserClassDeclaration6.js b/tests/baselines/reference/parserClassDeclaration6.js
index 1423edfe037..9b5d7906a90 100644
--- a/tests/baselines/reference/parserClassDeclaration6.js
+++ b/tests/baselines/reference/parserClassDeclaration6.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause2.js b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause2.js
index aa0679bb8f5..f128f279fda 100644
--- a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause2.js
+++ b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause2.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause4.js b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause4.js
index 1308c7c194b..5c0858c5c79 100644
--- a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause4.js
+++ b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause4.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause5.js b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause5.js
index b1471628fbd..e4fbdb65c3e 100644
--- a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause5.js
+++ b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause5.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/parserGenericsInTypeContexts1.js b/tests/baselines/reference/parserGenericsInTypeContexts1.js
index 641d296dc43..290176d0968 100644
--- a/tests/baselines/reference/parserGenericsInTypeContexts1.js
+++ b/tests/baselines/reference/parserGenericsInTypeContexts1.js
@@ -26,7 +26,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/parserGenericsInTypeContexts2.js b/tests/baselines/reference/parserGenericsInTypeContexts2.js
index b0f14a090ae..e0b858510b9 100644
--- a/tests/baselines/reference/parserGenericsInTypeContexts2.js
+++ b/tests/baselines/reference/parserGenericsInTypeContexts2.js
@@ -26,7 +26,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/partiallyAnnotatedFunctionInferenceError.js b/tests/baselines/reference/partiallyAnnotatedFunctionInferenceError.js
index 9702595fffb..6baddeade3d 100644
--- a/tests/baselines/reference/partiallyAnnotatedFunctionInferenceError.js
+++ b/tests/baselines/reference/partiallyAnnotatedFunctionInferenceError.js
@@ -29,7 +29,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/partiallyAnnotatedFunctionInferenceWithTypeParameter.js b/tests/baselines/reference/partiallyAnnotatedFunctionInferenceWithTypeParameter.js
index d20b35625e9..b0a85ce0613 100644
--- a/tests/baselines/reference/partiallyAnnotatedFunctionInferenceWithTypeParameter.js
+++ b/tests/baselines/reference/partiallyAnnotatedFunctionInferenceWithTypeParameter.js
@@ -48,7 +48,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/primitiveMembers.js b/tests/baselines/reference/primitiveMembers.js
index 7b94b555eb1..0e52fcfca69 100644
--- a/tests/baselines/reference/primitiveMembers.js
+++ b/tests/baselines/reference/primitiveMembers.js
@@ -63,7 +63,7 @@ var baz = (function () {
 var foo = (function (_super) {
     __extends(foo, _super);
     function foo() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     foo.prototype.bar = function () { return undefined; };
     ;
diff --git a/tests/baselines/reference/privacyClass.js b/tests/baselines/reference/privacyClass.js
index 7e56edf2cf1..fe700c2594d 100644
--- a/tests/baselines/reference/privacyClass.js
+++ b/tests/baselines/reference/privacyClass.js
@@ -152,21 +152,21 @@ var m1;
     var m1_C1_private = (function (_super) {
         __extends(m1_C1_private, _super);
         function m1_C1_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C1_private;
     }(m1_c_public));
     var m1_C2_private = (function (_super) {
         __extends(m1_C2_private, _super);
         function m1_C2_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C2_private;
     }(m1_c_private));
     var m1_C3_public = (function (_super) {
         __extends(m1_C3_public, _super);
         function m1_C3_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C3_public;
     }(m1_c_public));
@@ -174,7 +174,7 @@ var m1;
     var m1_C4_public = (function (_super) {
         __extends(m1_C4_public, _super);
         function m1_C4_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C4_public;
     }(m1_c_private));
@@ -204,21 +204,21 @@ var m1;
     var m1_C9_private = (function (_super) {
         __extends(m1_C9_private, _super);
         function m1_C9_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C9_private;
     }(m1_c_public));
     var m1_C10_private = (function (_super) {
         __extends(m1_C10_private, _super);
         function m1_C10_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C10_private;
     }(m1_c_private));
     var m1_C11_public = (function (_super) {
         __extends(m1_C11_public, _super);
         function m1_C11_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C11_public;
     }(m1_c_public));
@@ -226,7 +226,7 @@ var m1;
     var m1_C12_public = (function (_super) {
         __extends(m1_C12_public, _super);
         function m1_C12_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C12_public;
     }(m1_c_private));
@@ -250,21 +250,21 @@ var m2;
     var m2_C1_private = (function (_super) {
         __extends(m2_C1_private, _super);
         function m2_C1_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m2_C1_private;
     }(m2_c_public));
     var m2_C2_private = (function (_super) {
         __extends(m2_C2_private, _super);
         function m2_C2_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m2_C2_private;
     }(m2_c_private));
     var m2_C3_public = (function (_super) {
         __extends(m2_C3_public, _super);
         function m2_C3_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m2_C3_public;
     }(m2_c_public));
@@ -272,7 +272,7 @@ var m2;
     var m2_C4_public = (function (_super) {
         __extends(m2_C4_public, _super);
         function m2_C4_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m2_C4_public;
     }(m2_c_private));
@@ -302,21 +302,21 @@ var m2;
     var m2_C9_private = (function (_super) {
         __extends(m2_C9_private, _super);
         function m2_C9_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m2_C9_private;
     }(m2_c_public));
     var m2_C10_private = (function (_super) {
         __extends(m2_C10_private, _super);
         function m2_C10_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m2_C10_private;
     }(m2_c_private));
     var m2_C11_public = (function (_super) {
         __extends(m2_C11_public, _super);
         function m2_C11_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m2_C11_public;
     }(m2_c_public));
@@ -324,7 +324,7 @@ var m2;
     var m2_C12_public = (function (_super) {
         __extends(m2_C12_public, _super);
         function m2_C12_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m2_C12_public;
     }(m2_c_private));
@@ -346,21 +346,21 @@ var glo_c_private = (function () {
 var glo_C1_private = (function (_super) {
     __extends(glo_C1_private, _super);
     function glo_C1_private() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C1_private;
 }(glo_c_public));
 var glo_C2_private = (function (_super) {
     __extends(glo_C2_private, _super);
     function glo_C2_private() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C2_private;
 }(glo_c_private));
 var glo_C3_public = (function (_super) {
     __extends(glo_C3_public, _super);
     function glo_C3_public() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C3_public;
 }(glo_c_public));
@@ -368,7 +368,7 @@ exports.glo_C3_public = glo_C3_public;
 var glo_C4_public = (function (_super) {
     __extends(glo_C4_public, _super);
     function glo_C4_public() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C4_public;
 }(glo_c_private));
@@ -398,21 +398,21 @@ exports.glo_C8_public = glo_C8_public;
 var glo_C9_private = (function (_super) {
     __extends(glo_C9_private, _super);
     function glo_C9_private() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C9_private;
 }(glo_c_public));
 var glo_C10_private = (function (_super) {
     __extends(glo_C10_private, _super);
     function glo_C10_private() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C10_private;
 }(glo_c_private));
 var glo_C11_public = (function (_super) {
     __extends(glo_C11_public, _super);
     function glo_C11_public() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C11_public;
 }(glo_c_public));
@@ -420,7 +420,7 @@ exports.glo_C11_public = glo_C11_public;
 var glo_C12_public = (function (_super) {
     __extends(glo_C12_public, _super);
     function glo_C12_public() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C12_public;
 }(glo_c_private));
diff --git a/tests/baselines/reference/privacyClassExtendsClauseDeclFile.js b/tests/baselines/reference/privacyClassExtendsClauseDeclFile.js
index e0828809416..1962d4b1d0d 100644
--- a/tests/baselines/reference/privacyClassExtendsClauseDeclFile.js
+++ b/tests/baselines/reference/privacyClassExtendsClauseDeclFile.js
@@ -122,21 +122,21 @@ var publicModule;
     var privateClassExtendingPublicClassInModule = (function (_super) {
         __extends(privateClassExtendingPublicClassInModule, _super);
         function privateClassExtendingPublicClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return privateClassExtendingPublicClassInModule;
     }(publicClassInPublicModule));
     var privateClassExtendingPrivateClassInModule = (function (_super) {
         __extends(privateClassExtendingPrivateClassInModule, _super);
         function privateClassExtendingPrivateClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return privateClassExtendingPrivateClassInModule;
     }(privateClassInPublicModule));
     var publicClassExtendingPublicClassInModule = (function (_super) {
         __extends(publicClassExtendingPublicClassInModule, _super);
         function publicClassExtendingPublicClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return publicClassExtendingPublicClassInModule;
     }(publicClassInPublicModule));
@@ -144,7 +144,7 @@ var publicModule;
     var publicClassExtendingPrivateClassInModule = (function (_super) {
         __extends(publicClassExtendingPrivateClassInModule, _super);
         function publicClassExtendingPrivateClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return publicClassExtendingPrivateClassInModule;
     }(privateClassInPublicModule));
@@ -152,14 +152,14 @@ var publicModule;
     var privateClassExtendingFromPrivateModuleClass = (function (_super) {
         __extends(privateClassExtendingFromPrivateModuleClass, _super);
         function privateClassExtendingFromPrivateModuleClass() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return privateClassExtendingFromPrivateModuleClass;
     }(privateModule.publicClassInPrivateModule));
     var publicClassExtendingFromPrivateModuleClass = (function (_super) {
         __extends(publicClassExtendingFromPrivateModuleClass, _super);
         function publicClassExtendingFromPrivateModuleClass() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return publicClassExtendingFromPrivateModuleClass;
     }(privateModule.publicClassInPrivateModule));
@@ -183,21 +183,21 @@ var privateModule;
     var privateClassExtendingPublicClassInModule = (function (_super) {
         __extends(privateClassExtendingPublicClassInModule, _super);
         function privateClassExtendingPublicClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return privateClassExtendingPublicClassInModule;
     }(publicClassInPrivateModule));
     var privateClassExtendingPrivateClassInModule = (function (_super) {
         __extends(privateClassExtendingPrivateClassInModule, _super);
         function privateClassExtendingPrivateClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return privateClassExtendingPrivateClassInModule;
     }(privateClassInPrivateModule));
     var publicClassExtendingPublicClassInModule = (function (_super) {
         __extends(publicClassExtendingPublicClassInModule, _super);
         function publicClassExtendingPublicClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return publicClassExtendingPublicClassInModule;
     }(publicClassInPrivateModule));
@@ -205,7 +205,7 @@ var privateModule;
     var publicClassExtendingPrivateClassInModule = (function (_super) {
         __extends(publicClassExtendingPrivateClassInModule, _super);
         function publicClassExtendingPrivateClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return publicClassExtendingPrivateClassInModule;
     }(privateClassInPrivateModule));
@@ -213,14 +213,14 @@ var privateModule;
     var privateClassExtendingFromPrivateModuleClass = (function (_super) {
         __extends(privateClassExtendingFromPrivateModuleClass, _super);
         function privateClassExtendingFromPrivateModuleClass() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return privateClassExtendingFromPrivateModuleClass;
     }(privateModule.publicClassInPrivateModule));
     var publicClassExtendingFromPrivateModuleClass = (function (_super) {
         __extends(publicClassExtendingFromPrivateModuleClass, _super);
         function publicClassExtendingFromPrivateModuleClass() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return publicClassExtendingFromPrivateModuleClass;
     }(privateModule.publicClassInPrivateModule));
@@ -242,21 +242,21 @@ var privateClass = (function () {
 var privateClassExtendingPublicClass = (function (_super) {
     __extends(privateClassExtendingPublicClass, _super);
     function privateClassExtendingPublicClass() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return privateClassExtendingPublicClass;
 }(publicClass));
 var privateClassExtendingPrivateClassInModule = (function (_super) {
     __extends(privateClassExtendingPrivateClassInModule, _super);
     function privateClassExtendingPrivateClassInModule() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return privateClassExtendingPrivateClassInModule;
 }(privateClass));
 var publicClassExtendingPublicClass = (function (_super) {
     __extends(publicClassExtendingPublicClass, _super);
     function publicClassExtendingPublicClass() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return publicClassExtendingPublicClass;
 }(publicClass));
@@ -264,7 +264,7 @@ exports.publicClassExtendingPublicClass = publicClassExtendingPublicClass;
 var publicClassExtendingPrivateClass = (function (_super) {
     __extends(publicClassExtendingPrivateClass, _super);
     function publicClassExtendingPrivateClass() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return publicClassExtendingPrivateClass;
 }(privateClass));
@@ -272,14 +272,14 @@ exports.publicClassExtendingPrivateClass = publicClassExtendingPrivateClass;
 var privateClassExtendingFromPrivateModuleClass = (function (_super) {
     __extends(privateClassExtendingFromPrivateModuleClass, _super);
     function privateClassExtendingFromPrivateModuleClass() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return privateClassExtendingFromPrivateModuleClass;
 }(privateModule.publicClassInPrivateModule));
 var publicClassExtendingFromPrivateModuleClass = (function (_super) {
     __extends(publicClassExtendingFromPrivateModuleClass, _super);
     function publicClassExtendingFromPrivateModuleClass() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return publicClassExtendingFromPrivateModuleClass;
 }(privateModule.publicClassInPrivateModule));
@@ -308,21 +308,21 @@ var publicModuleInGlobal;
     var privateClassExtendingPublicClassInModule = (function (_super) {
         __extends(privateClassExtendingPublicClassInModule, _super);
         function privateClassExtendingPublicClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return privateClassExtendingPublicClassInModule;
     }(publicClassInPublicModule));
     var privateClassExtendingPrivateClassInModule = (function (_super) {
         __extends(privateClassExtendingPrivateClassInModule, _super);
         function privateClassExtendingPrivateClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return privateClassExtendingPrivateClassInModule;
     }(privateClassInPublicModule));
     var publicClassExtendingPublicClassInModule = (function (_super) {
         __extends(publicClassExtendingPublicClassInModule, _super);
         function publicClassExtendingPublicClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return publicClassExtendingPublicClassInModule;
     }(publicClassInPublicModule));
@@ -330,7 +330,7 @@ var publicModuleInGlobal;
     var publicClassExtendingPrivateClassInModule = (function (_super) {
         __extends(publicClassExtendingPrivateClassInModule, _super);
         function publicClassExtendingPrivateClassInModule() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return publicClassExtendingPrivateClassInModule;
     }(privateClassInPublicModule));
@@ -344,7 +344,7 @@ var publicClassInGlobal = (function () {
 var publicClassExtendingPublicClassInGlobal = (function (_super) {
     __extends(publicClassExtendingPublicClassInGlobal, _super);
     function publicClassExtendingPublicClassInGlobal() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return publicClassExtendingPublicClassInGlobal;
 }(publicClassInGlobal));
diff --git a/tests/baselines/reference/privacyGloClass.js b/tests/baselines/reference/privacyGloClass.js
index fa769a606ae..82c7cc6dfaf 100644
--- a/tests/baselines/reference/privacyGloClass.js
+++ b/tests/baselines/reference/privacyGloClass.js
@@ -84,21 +84,21 @@ var m1;
     var m1_C1_private = (function (_super) {
         __extends(m1_C1_private, _super);
         function m1_C1_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C1_private;
     }(m1_c_public));
     var m1_C2_private = (function (_super) {
         __extends(m1_C2_private, _super);
         function m1_C2_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C2_private;
     }(m1_c_private));
     var m1_C3_public = (function (_super) {
         __extends(m1_C3_public, _super);
         function m1_C3_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C3_public;
     }(m1_c_public));
@@ -106,7 +106,7 @@ var m1;
     var m1_C4_public = (function (_super) {
         __extends(m1_C4_public, _super);
         function m1_C4_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C4_public;
     }(m1_c_private));
@@ -136,21 +136,21 @@ var m1;
     var m1_C9_private = (function (_super) {
         __extends(m1_C9_private, _super);
         function m1_C9_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C9_private;
     }(m1_c_public));
     var m1_C10_private = (function (_super) {
         __extends(m1_C10_private, _super);
         function m1_C10_private() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C10_private;
     }(m1_c_private));
     var m1_C11_public = (function (_super) {
         __extends(m1_C11_public, _super);
         function m1_C11_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C11_public;
     }(m1_c_public));
@@ -158,7 +158,7 @@ var m1;
     var m1_C12_public = (function (_super) {
         __extends(m1_C12_public, _super);
         function m1_C12_public() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return m1_C12_public;
     }(m1_c_private));
@@ -174,7 +174,7 @@ var glo_c_public = (function () {
 var glo_C3_public = (function (_super) {
     __extends(glo_C3_public, _super);
     function glo_C3_public() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C3_public;
 }(glo_c_public));
@@ -186,7 +186,7 @@ var glo_C7_public = (function () {
 var glo_C11_public = (function (_super) {
     __extends(glo_C11_public, _super);
     function glo_C11_public() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return glo_C11_public;
 }(glo_c_public));
diff --git a/tests/baselines/reference/privateAccessInSubclass1.js b/tests/baselines/reference/privateAccessInSubclass1.js
index 21ff4793fb3..5d05e7ce3c5 100644
--- a/tests/baselines/reference/privateAccessInSubclass1.js
+++ b/tests/baselines/reference/privateAccessInSubclass1.js
@@ -23,7 +23,7 @@ var Base = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.myMethod = function () {
         this.options;
diff --git a/tests/baselines/reference/privateInstanceMemberAccessibility.js b/tests/baselines/reference/privateInstanceMemberAccessibility.js
index 6fa05178f91..26cbc4e9b51 100644
--- a/tests/baselines/reference/privateInstanceMemberAccessibility.js
+++ b/tests/baselines/reference/privateInstanceMemberAccessibility.js
@@ -27,7 +27,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.x = _super.prototype.foo; // error
         _this.z = _super.prototype.foo; // error
         return _this;
diff --git a/tests/baselines/reference/privateProtectedMembersAreNotAccessibleDestructuring.js b/tests/baselines/reference/privateProtectedMembersAreNotAccessibleDestructuring.js
index b732661edfc..a93a90e6096 100644
--- a/tests/baselines/reference/privateProtectedMembersAreNotAccessibleDestructuring.js
+++ b/tests/baselines/reference/privateProtectedMembersAreNotAccessibleDestructuring.js
@@ -40,7 +40,7 @@ var K = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.prototype.m2 = function () {
         var a = this.priv; // error
diff --git a/tests/baselines/reference/privateStaticMemberAccessibility.js b/tests/baselines/reference/privateStaticMemberAccessibility.js
index c1897e8503a..3d258c05107 100644
--- a/tests/baselines/reference/privateStaticMemberAccessibility.js
+++ b/tests/baselines/reference/privateStaticMemberAccessibility.js
@@ -22,7 +22,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.bing = function () { return Base.foo; }; // error
         return _this;
     }
diff --git a/tests/baselines/reference/privateStaticNotAccessibleInClodule2.js b/tests/baselines/reference/privateStaticNotAccessibleInClodule2.js
index a93823654d4..43f9547ed5d 100644
--- a/tests/baselines/reference/privateStaticNotAccessibleInClodule2.js
+++ b/tests/baselines/reference/privateStaticNotAccessibleInClodule2.js
@@ -29,7 +29,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/amd/testGlo.js b/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/amd/testGlo.js
index 99a4842f636..a9e7e35691a 100644
--- a/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/amd/testGlo.js
+++ b/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/amd/testGlo.js
@@ -14,7 +14,7 @@ var m2;
     var class1 = (function (_super) {
         __extends(class1, _super);
         function class1() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class1;
     }(m2.mExported.me.class1));
@@ -27,7 +27,7 @@ var m2;
     var class2 = (function (_super) {
         __extends(class2, _super);
         function class2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class2;
     }(m2.mExported.me.class1));
@@ -40,7 +40,7 @@ var m2;
     var class3 = (function (_super) {
         __extends(class3, _super);
         function class3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class3;
     }(mNonExported.mne.class1));
@@ -53,7 +53,7 @@ var m2;
     var class4 = (function (_super) {
         __extends(class4, _super);
         function class4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class4;
     }(mNonExported.mne.class1));
diff --git a/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/node/testGlo.js b/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/node/testGlo.js
index 99a4842f636..a9e7e35691a 100644
--- a/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/node/testGlo.js
+++ b/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/node/testGlo.js
@@ -14,7 +14,7 @@ var m2;
     var class1 = (function (_super) {
         __extends(class1, _super);
         function class1() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class1;
     }(m2.mExported.me.class1));
@@ -27,7 +27,7 @@ var m2;
     var class2 = (function (_super) {
         __extends(class2, _super);
         function class2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class2;
     }(m2.mExported.me.class1));
@@ -40,7 +40,7 @@ var m2;
     var class3 = (function (_super) {
         __extends(class3, _super);
         function class3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class3;
     }(mNonExported.mne.class1));
@@ -53,7 +53,7 @@ var m2;
     var class4 = (function (_super) {
         __extends(class4, _super);
         function class4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class4;
     }(mNonExported.mne.class1));
diff --git a/tests/baselines/reference/project/prologueEmit/amd/out.js b/tests/baselines/reference/project/prologueEmit/amd/out.js
index 7ee160b82ef..4e2f220a2e7 100644
--- a/tests/baselines/reference/project/prologueEmit/amd/out.js
+++ b/tests/baselines/reference/project/prologueEmit/amd/out.js
@@ -18,7 +18,7 @@ var m;
     var child = (function (_super) {
         __extends(child, _super);
         function child() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return child;
     }(base));
diff --git a/tests/baselines/reference/project/prologueEmit/node/out.js b/tests/baselines/reference/project/prologueEmit/node/out.js
index 7ee160b82ef..4e2f220a2e7 100644
--- a/tests/baselines/reference/project/prologueEmit/node/out.js
+++ b/tests/baselines/reference/project/prologueEmit/node/out.js
@@ -18,7 +18,7 @@ var m;
     var child = (function (_super) {
         __extends(child, _super);
         function child() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return child;
     }(base));
diff --git a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.js b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.js
index b793b07534c..5c4a53e1af1 100644
--- a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.js
+++ b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.js
@@ -7,7 +7,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var ClassC = (function (_super) {
     __extends(ClassC, _super);
     function ClassC() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ClassC;
 }(test.ClassA));
diff --git a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.js b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.js
index b793b07534c..5c4a53e1af1 100644
--- a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.js
+++ b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.js
@@ -7,7 +7,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var ClassC = (function (_super) {
     __extends(ClassC, _super);
     function ClassC() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ClassC;
 }(test.ClassA));
diff --git a/tests/baselines/reference/propertiesAndIndexers.js b/tests/baselines/reference/propertiesAndIndexers.js
index dff86f3954e..62cd3439e35 100644
--- a/tests/baselines/reference/propertiesAndIndexers.js
+++ b/tests/baselines/reference/propertiesAndIndexers.js
@@ -65,7 +65,7 @@ var P = (function () {
 var Q = (function (_super) {
     __extends(Q, _super);
     function Q() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Q;
 }(P));
diff --git a/tests/baselines/reference/propertyAccess.js b/tests/baselines/reference/propertyAccess.js
index 0a4c9082a21..66f41d392da 100644
--- a/tests/baselines/reference/propertyAccess.js
+++ b/tests/baselines/reference/propertyAccess.js
@@ -164,7 +164,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
diff --git a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints2.js b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints2.js
index d36d7e27efe..dfcd60fb7ed 100644
--- a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints2.js
+++ b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints2.js
@@ -97,7 +97,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.bar = function () {
         return '';
diff --git a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints3.js b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints3.js
index 4aedfe12b04..9a07927c219 100644
--- a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints3.js
+++ b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints3.js
@@ -72,7 +72,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.bar = function () {
         return '';
diff --git a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints5.js b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints5.js
index 3cb14438141..adf39f857ef 100644
--- a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints5.js
+++ b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints5.js
@@ -59,7 +59,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.bar = function () {
         return '';
diff --git a/tests/baselines/reference/protectedClassPropertyAccessibleWithinNestedSubclass.js b/tests/baselines/reference/protectedClassPropertyAccessibleWithinNestedSubclass.js
index 429dfdf6b14..b0f4a723b94 100644
--- a/tests/baselines/reference/protectedClassPropertyAccessibleWithinNestedSubclass.js
+++ b/tests/baselines/reference/protectedClassPropertyAccessibleWithinNestedSubclass.js
@@ -52,7 +52,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(C.prototype, "y", {
         get: function () { return this.x; },
@@ -93,7 +93,7 @@ var C = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return E;
 }(C));
diff --git a/tests/baselines/reference/protectedClassPropertyAccessibleWithinNestedSubclass1.js b/tests/baselines/reference/protectedClassPropertyAccessibleWithinNestedSubclass1.js
index 0571b85ea9e..49ea1f06cbd 100644
--- a/tests/baselines/reference/protectedClassPropertyAccessibleWithinNestedSubclass1.js
+++ b/tests/baselines/reference/protectedClassPropertyAccessibleWithinNestedSubclass1.js
@@ -147,7 +147,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.prototype.method1 = function () {
         var B = (function () {
@@ -173,7 +173,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived2.prototype.method2 = function () {
         var C = (function () {
@@ -199,7 +199,7 @@ var Derived2 = (function (_super) {
 var Derived3 = (function (_super) {
     __extends(Derived3, _super);
     function Derived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived3.prototype.method3 = function () {
         var D = (function () {
@@ -225,7 +225,7 @@ var Derived3 = (function (_super) {
 var Derived4 = (function (_super) {
     __extends(Derived4, _super);
     function Derived4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived4.prototype.method4 = function () {
         var E = (function () {
diff --git a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass.js b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass.js
index a10b39b402e..c7af9d943e7 100644
--- a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass.js
+++ b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass.js
@@ -34,7 +34,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(C.prototype, "y", {
         get: function () { return this.x; },
diff --git a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass2.js b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass2.js
index a404b8049bc..a1fe3a78385 100644
--- a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass2.js
+++ b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass2.js
@@ -120,7 +120,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.prototype.method1 = function () {
         var b;
@@ -139,7 +139,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived2.prototype.method2 = function () {
         var b;
@@ -158,7 +158,7 @@ var Derived2 = (function (_super) {
 var Derived3 = (function (_super) {
     __extends(Derived3, _super);
     function Derived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived3.prototype.method3 = function () {
         var b;
@@ -177,7 +177,7 @@ var Derived3 = (function (_super) {
 var Derived4 = (function (_super) {
     __extends(Derived4, _super);
     function Derived4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived4.prototype.method4 = function () {
         var b;
diff --git a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass3.js b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass3.js
index 7d449bdcbd4..c5858b2df42 100644
--- a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass3.js
+++ b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass3.js
@@ -30,7 +30,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.prototype.method1 = function () {
         this.x; // OK, accessed within a subclass of the declaring class
diff --git a/tests/baselines/reference/protectedInstanceMemberAccessibility.js b/tests/baselines/reference/protectedInstanceMemberAccessibility.js
index 3259d401270..61729cf1eb6 100644
--- a/tests/baselines/reference/protectedInstanceMemberAccessibility.js
+++ b/tests/baselines/reference/protectedInstanceMemberAccessibility.js
@@ -61,7 +61,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.g = function () {
         var t1 = this.x;
@@ -93,7 +93,7 @@ var B = (function (_super) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/protectedMembers.js b/tests/baselines/reference/protectedMembers.js
index 46b4691dff7..9dc172f1080 100644
--- a/tests/baselines/reference/protectedMembers.js
+++ b/tests/baselines/reference/protectedMembers.js
@@ -137,7 +137,7 @@ var C1 = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C2.prototype.f = function () {
         return _super.prototype.f.call(this) + this.x;
@@ -151,7 +151,7 @@ var C2 = (function (_super) {
 var C3 = (function (_super) {
     __extends(C3, _super);
     function C3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C3.prototype.f = function () {
         return _super.prototype.f.call(this);
@@ -187,14 +187,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     C.foo = function (a, b, c, d, e) {
         a.x = 1; // Error, access must be through C or type derived from C
@@ -208,7 +208,7 @@ var C = (function (_super) {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
@@ -239,7 +239,7 @@ var A2 = (function () {
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A2));
@@ -252,7 +252,7 @@ var A3 = (function () {
 var B3 = (function (_super) {
     __extends(B3, _super);
     function B3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B3;
 }(A3));
diff --git a/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass.js b/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass.js
index ad1b1682aa7..cc88a85669a 100644
--- a/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass.js
+++ b/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass.js
@@ -63,7 +63,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.staticMethod1 = function () {
         Base.x; // OK, accessed within a class derived from their declaring class
@@ -76,7 +76,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived2.staticMethod2 = function () {
         Base.x; // OK, accessed within a class derived from their declaring class
@@ -89,7 +89,7 @@ var Derived2 = (function (_super) {
 var Derived3 = (function (_super) {
     __extends(Derived3, _super);
     function Derived3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived3.staticMethod3 = function () {
         Base.x; // OK, accessed within a class derived from their declaring class
diff --git a/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass2.js b/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass2.js
index a2346b8be40..27987069ef9 100644
--- a/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass2.js
+++ b/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass2.js
@@ -38,7 +38,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.staticMethod1 = function () {
         this.x; // OK, accessed within a class derived from their declaring class
@@ -49,7 +49,7 @@ var Derived1 = (function (_super) {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived2.staticMethod3 = function () {
         this.x; // OK, accessed within a class derived from their declaring class
diff --git a/tests/baselines/reference/qualifiedName_entity-name-resolution-does-not-affect-class-heritage.js b/tests/baselines/reference/qualifiedName_entity-name-resolution-does-not-affect-class-heritage.js
index a881eb55a18..516c2bb42b1 100644
--- a/tests/baselines/reference/qualifiedName_entity-name-resolution-does-not-affect-class-heritage.js
+++ b/tests/baselines/reference/qualifiedName_entity-name-resolution-does-not-affect-class-heritage.js
@@ -19,7 +19,7 @@ var Alpha;
 var Beta = (function (_super) {
     __extends(Beta, _super);
     function Beta() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Beta;
 }(Alpha.x));
diff --git a/tests/baselines/reference/recursiveBaseCheck3.js b/tests/baselines/reference/recursiveBaseCheck3.js
index 250a9e0b618..81f9b83699c 100644
--- a/tests/baselines/reference/recursiveBaseCheck3.js
+++ b/tests/baselines/reference/recursiveBaseCheck3.js
@@ -13,14 +13,14 @@ var __extends = (this && this.__extends) || function (d, b) {
 var A = (function (_super) {
     __extends(A, _super);
     function A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return A;
 }(C));
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/recursiveBaseCheck4.js b/tests/baselines/reference/recursiveBaseCheck4.js
index 7f0c6b5f95d..ee7cdc13da5 100644
--- a/tests/baselines/reference/recursiveBaseCheck4.js
+++ b/tests/baselines/reference/recursiveBaseCheck4.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var M = (function (_super) {
     __extends(M, _super);
     function M() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return M;
 }(M));
diff --git a/tests/baselines/reference/recursiveBaseCheck6.js b/tests/baselines/reference/recursiveBaseCheck6.js
index 53a608baeca..795c065307f 100644
--- a/tests/baselines/reference/recursiveBaseCheck6.js
+++ b/tests/baselines/reference/recursiveBaseCheck6.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var S18 = (function (_super) {
     __extends(S18, _super);
     function S18() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return S18;
 }(S18));
diff --git a/tests/baselines/reference/recursiveBaseConstructorCreation1.js b/tests/baselines/reference/recursiveBaseConstructorCreation1.js
index 344750974cb..8ba0f420710 100644
--- a/tests/baselines/reference/recursiveBaseConstructorCreation1.js
+++ b/tests/baselines/reference/recursiveBaseConstructorCreation1.js
@@ -21,7 +21,7 @@ var C1 = (function () {
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(C1));
diff --git a/tests/baselines/reference/recursiveClassInstantiationsWithDefaultConstructors.js b/tests/baselines/reference/recursiveClassInstantiationsWithDefaultConstructors.js
index 34aa110b7ee..9b37165d28b 100644
--- a/tests/baselines/reference/recursiveClassInstantiationsWithDefaultConstructors.js
+++ b/tests/baselines/reference/recursiveClassInstantiationsWithDefaultConstructors.js
@@ -28,7 +28,7 @@ var TypeScript2;
     var MemberNameArray = (function (_super) {
         __extends(MemberNameArray, _super);
         function MemberNameArray() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return MemberNameArray;
     }(MemberName));
diff --git a/tests/baselines/reference/recursiveClassReferenceTest.js b/tests/baselines/reference/recursiveClassReferenceTest.js
index a2cf3319474..62025c3def7 100644
--- a/tests/baselines/reference/recursiveClassReferenceTest.js
+++ b/tests/baselines/reference/recursiveClassReferenceTest.js
@@ -188,7 +188,7 @@ var AbstractMode = (function () {
                 var Mode = (function (_super) {
                     __extends(Mode, _super);
                     function Mode() {
-                        return _super.apply(this, arguments) || this;
+                        return _super !== null && _super.apply(this, arguments) || this;
                     }
                     // scenario 2
                     Mode.prototype.getInitialState = function () {
diff --git a/tests/baselines/reference/recursiveClassReferenceTest.sourcemap.txt b/tests/baselines/reference/recursiveClassReferenceTest.sourcemap.txt
index f99a062e2c6..c7f6f47196d 100644
--- a/tests/baselines/reference/recursiveClassReferenceTest.sourcemap.txt
+++ b/tests/baselines/reference/recursiveClassReferenceTest.sourcemap.txt
@@ -1618,11 +1618,11 @@ sourceFile:recursiveClassReferenceTest.ts
 ---
 >>>                    function Mode() {
 1 >^^^^^^^^^^^^^^^^^^^^
-2 >                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+2 >                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
 1 >Emitted(85, 21) Source(91, 2) + SourceIndex(0)
 ---
->>>                        return _super.apply(this, arguments) || this;
+>>>                        return _super !== null && _super.apply(this, arguments) || this;
 >>>                    }
 1->^^^^^^^^^^^^^^^^^^^^
 2 >                    ^
diff --git a/tests/baselines/reference/recursiveComplicatedClasses.js b/tests/baselines/reference/recursiveComplicatedClasses.js
index 8441ff9e15a..3af1f2023fa 100644
--- a/tests/baselines/reference/recursiveComplicatedClasses.js
+++ b/tests/baselines/reference/recursiveComplicatedClasses.js
@@ -51,21 +51,21 @@ var Symbol = (function () {
 var InferenceSymbol = (function (_super) {
     __extends(InferenceSymbol, _super);
     function InferenceSymbol() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return InferenceSymbol;
 }(Symbol));
 var ParameterSymbol = (function (_super) {
     __extends(ParameterSymbol, _super);
     function ParameterSymbol() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ParameterSymbol;
 }(InferenceSymbol));
 var TypeSymbol = (function (_super) {
     __extends(TypeSymbol, _super);
     function TypeSymbol() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return TypeSymbol;
 }(InferenceSymbol));
diff --git a/tests/baselines/reference/recursivelySpecializedConstructorDeclaration.js b/tests/baselines/reference/recursivelySpecializedConstructorDeclaration.js
index 76224741e60..7b39ffb828d 100644
--- a/tests/baselines/reference/recursivelySpecializedConstructorDeclaration.js
+++ b/tests/baselines/reference/recursivelySpecializedConstructorDeclaration.js
@@ -52,7 +52,7 @@ var MsPortal;
                 var ViewModel = (function (_super) {
                     __extends(ViewModel, _super);
                     function ViewModel() {
-                        return _super.apply(this, arguments) || this;
+                        return _super !== null && _super.apply(this, arguments) || this;
                     }
                     return ViewModel;
                 }(ItemValue));
diff --git a/tests/baselines/reference/reexportClassDefinition.js b/tests/baselines/reference/reexportClassDefinition.js
index a75a90d4d86..f374e7104b0 100644
--- a/tests/baselines/reference/reexportClassDefinition.js
+++ b/tests/baselines/reference/reexportClassDefinition.js
@@ -42,7 +42,7 @@ var foo2 = require("./foo2");
 var x = (function (_super) {
     __extends(x, _super);
     function x() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return x;
 }(foo2.x));
diff --git a/tests/baselines/reference/resolvingClassDeclarationWhenInBaseTypeResolution.js b/tests/baselines/reference/resolvingClassDeclarationWhenInBaseTypeResolution.js
index 94dc537298a..d0763988ae2 100644
--- a/tests/baselines/reference/resolvingClassDeclarationWhenInBaseTypeResolution.js
+++ b/tests/baselines/reference/resolvingClassDeclarationWhenInBaseTypeResolution.js
@@ -1030,7 +1030,7 @@ var rionegrensis;
     var caniventer = (function (_super) {
         __extends(caniventer, _super);
         function caniventer() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         caniventer.prototype.salomonseni = function () {
             var _this = this;
@@ -1068,7 +1068,7 @@ var rionegrensis;
     var veraecrucis = (function (_super) {
         __extends(veraecrucis, _super);
         function veraecrucis() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         veraecrucis.prototype.naso = function () {
             var _this = this;
@@ -1247,7 +1247,7 @@ var julianae;
     var oralis = (function (_super) {
         __extends(oralis, _super);
         function oralis() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         oralis.prototype.cepapi = function () {
             var _this = this;
@@ -1333,7 +1333,7 @@ var julianae;
     var sumatrana = (function (_super) {
         __extends(sumatrana, _super);
         function sumatrana() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         sumatrana.prototype.wolffsohni = function () {
             var _this = this;
@@ -1533,7 +1533,7 @@ var julianae;
     var durangae = (function (_super) {
         __extends(durangae, _super);
         function durangae() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         durangae.prototype.Californium = function () {
             var _this = this;
@@ -1607,7 +1607,7 @@ var Lanthanum;
     var nitidus = (function (_super) {
         __extends(nitidus, _super);
         function nitidus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         nitidus.prototype.granatensis = function () {
             var _this = this;
@@ -1675,7 +1675,7 @@ var Lanthanum;
     var megalonyx = (function (_super) {
         __extends(megalonyx, _super);
         function megalonyx() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         megalonyx.prototype.phillipsii = function () {
             var _this = this;
@@ -1824,7 +1824,7 @@ var rendalli;
     var zuluensis = (function (_super) {
         __extends(zuluensis, _super);
         function zuluensis() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         zuluensis.prototype.telfairi = function () {
             var _this = this;
@@ -1982,7 +1982,7 @@ var rendalli;
     var crenulata = (function (_super) {
         __extends(crenulata, _super);
         function crenulata() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         crenulata.prototype.salvanius = function () {
             var _this = this;
@@ -2065,7 +2065,7 @@ var trivirgatus;
     var mixtus = (function (_super) {
         __extends(mixtus, _super);
         function mixtus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         mixtus.prototype.ochrogaster = function () {
             var _this = this;
@@ -2306,7 +2306,7 @@ var quasiater;
     var americanus = (function (_super) {
         __extends(americanus, _super);
         function americanus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         americanus.prototype.nasoloi = function () {
             var _this = this;
@@ -2341,7 +2341,7 @@ var lavali;
     var wilsoni = (function (_super) {
         __extends(wilsoni, _super);
         function wilsoni() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         wilsoni.prototype.setiger = function () {
             var _this = this;
@@ -2433,7 +2433,7 @@ var lavali;
     var otion = (function (_super) {
         __extends(otion, _super);
         function otion() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         otion.prototype.bonaerensis = function () {
             var _this = this;
@@ -2597,7 +2597,7 @@ var lavali;
     var thaeleri = (function (_super) {
         __extends(thaeleri, _super);
         function thaeleri() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         thaeleri.prototype.coromandra = function () {
             var _this = this;
@@ -2653,7 +2653,7 @@ var lavali;
     var lepturus = (function (_super) {
         __extends(lepturus, _super);
         function lepturus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         lepturus.prototype.ferrumequinum = function () {
             var _this = this;
@@ -2676,7 +2676,7 @@ var dogramacii;
     var robustulus = (function (_super) {
         __extends(robustulus, _super);
         function robustulus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         robustulus.prototype.fossor = function () {
             var _this = this;
@@ -2891,7 +2891,7 @@ var lutreolus;
     var schlegeli = (function (_super) {
         __extends(schlegeli, _super);
         function schlegeli() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         schlegeli.prototype.mittendorfi = function () {
             var _this = this;
@@ -3118,7 +3118,7 @@ var panglima;
     var amphibius = (function (_super) {
         __extends(amphibius, _super);
         function amphibius() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         amphibius.prototype.bottegi = function () {
             var _this = this;
@@ -3162,7 +3162,7 @@ var panglima;
     var fundatus = (function (_super) {
         __extends(fundatus, _super);
         function fundatus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         fundatus.prototype.crassulus = function () {
             var _this = this;
@@ -3188,7 +3188,7 @@ var panglima;
     var abidi = (function (_super) {
         __extends(abidi, _super);
         function abidi() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         abidi.prototype.greyii = function () {
             var _this = this;
@@ -3279,7 +3279,7 @@ var minutus;
     var himalayana = (function (_super) {
         __extends(himalayana, _super);
         function himalayana() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         himalayana.prototype.simoni = function () {
             var _this = this;
@@ -3362,7 +3362,7 @@ var caurinus;
     var mahaganus = (function (_super) {
         __extends(mahaganus, _super);
         function mahaganus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         mahaganus.prototype.martiniquensis = function () {
             var _this = this;
@@ -3436,7 +3436,7 @@ var howi;
     var angulatus = (function (_super) {
         __extends(angulatus, _super);
         function angulatus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         angulatus.prototype.pennatus = function () {
             var _this = this;
@@ -3518,7 +3518,7 @@ var sagitta;
     var walkeri = (function (_super) {
         __extends(walkeri, _super);
         function walkeri() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         walkeri.prototype.maracajuensis = function () {
             var _this = this;
@@ -3534,7 +3534,7 @@ var sagitta;
     var inez = (function (_super) {
         __extends(inez, _super);
         function inez() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         inez.prototype.vexillaris = function () {
             var _this = this;
@@ -3550,7 +3550,7 @@ var sagitta;
     var konganensis = (function (_super) {
         __extends(konganensis, _super);
         function konganensis() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return konganensis;
     }(imperfecta.lasiurus));
@@ -3561,7 +3561,7 @@ var panamensis;
     var linulus = (function (_super) {
         __extends(linulus, _super);
         function linulus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         linulus.prototype.goslingi = function () {
             var _this = this;
@@ -3712,7 +3712,7 @@ var samarensis;
     var pelurus = (function (_super) {
         __extends(pelurus, _super);
         function pelurus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         pelurus.prototype.Palladium = function () {
             var _this = this;
@@ -3798,7 +3798,7 @@ var samarensis;
     var fuscus = (function (_super) {
         __extends(fuscus, _super);
         function fuscus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         fuscus.prototype.planifrons = function () {
             var _this = this;
@@ -3958,7 +3958,7 @@ var samarensis;
     var leptoceros = (function (_super) {
         __extends(leptoceros, _super);
         function leptoceros() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         leptoceros.prototype.victus = function () {
             var _this = this;
@@ -3998,7 +3998,7 @@ var samarensis;
     var nigricans = (function (_super) {
         __extends(nigricans, _super);
         function nigricans() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         nigricans.prototype.woosnami = function () {
             var _this = this;
@@ -4023,7 +4023,7 @@ var dammermani;
     var pygmaea = (function (_super) {
         __extends(pygmaea, _super);
         function pygmaea() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         pygmaea.prototype.pajeros = function () {
             var _this = this;
@@ -4052,7 +4052,7 @@ var chrysaeolus;
     var sarasinorum = (function (_super) {
         __extends(sarasinorum, _super);
         function sarasinorum() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         sarasinorum.prototype.belzebul = function () {
             var _this = this;
@@ -4154,7 +4154,7 @@ var chrysaeolus;
     var oreas = (function (_super) {
         __extends(oreas, _super);
         function oreas() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         oreas.prototype.salamonis = function () {
             var _this = this;
@@ -4380,7 +4380,7 @@ var provocax;
     var melanoleuca = (function (_super) {
         __extends(melanoleuca, _super);
         function melanoleuca() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         melanoleuca.prototype.Neodymium = function () {
             var _this = this;
@@ -4422,7 +4422,7 @@ var provocax;
     var marcanoi = (function (_super) {
         __extends(marcanoi, _super);
         function marcanoi() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         marcanoi.prototype.formosae = function () {
             var _this = this;
@@ -4824,7 +4824,7 @@ var gabriellae;
     var klossii = (function (_super) {
         __extends(klossii, _super);
         function klossii() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return klossii;
     }(imperfecta.lasiurus));
@@ -5027,7 +5027,7 @@ var imperfecta;
     var ciliolabrum = (function (_super) {
         __extends(ciliolabrum, _super);
         function ciliolabrum() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         ciliolabrum.prototype.leschenaultii = function () {
             var _this = this;
@@ -5087,7 +5087,7 @@ var imperfecta;
     var sodyi = (function (_super) {
         __extends(sodyi, _super);
         function sodyi() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         sodyi.prototype.saundersiae = function () {
             var _this = this;
@@ -5151,7 +5151,7 @@ var imperfecta;
     var megaphyllus = (function (_super) {
         __extends(megaphyllus, _super);
         function megaphyllus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         megaphyllus.prototype.montana = function () {
             var _this = this;
@@ -5321,7 +5321,7 @@ var imperfecta;
     var cor = (function (_super) {
         __extends(cor, _super);
         function cor() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         cor.prototype.antinorii = function () {
             var _this = this;
@@ -5411,7 +5411,7 @@ var imperfecta;
     var germaini = (function (_super) {
         __extends(germaini, _super);
         function germaini() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         germaini.prototype.sharpei = function () {
             var _this = this;
@@ -5507,7 +5507,7 @@ var imperfecta;
     var melanops = (function (_super) {
         __extends(melanops, _super);
         function melanops() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         melanops.prototype.blarina = function () {
             var _this = this;
@@ -5595,7 +5595,7 @@ var imperfecta;
     var peninsulae = (function (_super) {
         __extends(peninsulae, _super);
         function peninsulae() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         peninsulae.prototype.aitkeni = function () {
             var _this = this;
@@ -5739,7 +5739,7 @@ var imperfecta;
     var Praseodymium = (function (_super) {
         __extends(Praseodymium, _super);
         function Praseodymium() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         Praseodymium.prototype.clara = function () {
             var _this = this;
@@ -5827,7 +5827,7 @@ var imperfecta;
     var johorensis = (function (_super) {
         __extends(johorensis, _super);
         function johorensis() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         johorensis.prototype.maini = function () {
             var _this = this;
@@ -5951,7 +5951,7 @@ var imperfecta;
     var psilurus = (function (_super) {
         __extends(psilurus, _super);
         function psilurus() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         psilurus.prototype.socialis = function () {
             var _this = this;
diff --git a/tests/baselines/reference/returnStatements.js b/tests/baselines/reference/returnStatements.js
index f786e994963..a2bdcce78fc 100644
--- a/tests/baselines/reference/returnStatements.js
+++ b/tests/baselines/reference/returnStatements.js
@@ -48,7 +48,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/scopeCheckExtendedClassInsidePublicMethod2.js b/tests/baselines/reference/scopeCheckExtendedClassInsidePublicMethod2.js
index 1474f8ab29a..2cc5630685d 100644
--- a/tests/baselines/reference/scopeCheckExtendedClassInsidePublicMethod2.js
+++ b/tests/baselines/reference/scopeCheckExtendedClassInsidePublicMethod2.js
@@ -22,7 +22,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.c = function () {
         v = 1;
diff --git a/tests/baselines/reference/scopeCheckExtendedClassInsideStaticMethod1.js b/tests/baselines/reference/scopeCheckExtendedClassInsideStaticMethod1.js
index 0baf0187009..9c06fce0a5f 100644
--- a/tests/baselines/reference/scopeCheckExtendedClassInsideStaticMethod1.js
+++ b/tests/baselines/reference/scopeCheckExtendedClassInsideStaticMethod1.js
@@ -22,7 +22,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.c = function () {
         v = 1;
diff --git a/tests/baselines/reference/shadowPrivateMembers.js b/tests/baselines/reference/shadowPrivateMembers.js
index 4906814f7eb..fa38a77fe40 100644
--- a/tests/baselines/reference/shadowPrivateMembers.js
+++ b/tests/baselines/reference/shadowPrivateMembers.js
@@ -18,7 +18,7 @@ var base = (function () {
 var derived = (function (_super) {
     __extends(derived, _super);
     function derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     derived.prototype.n = function () { };
     return derived;
diff --git a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js
index 4bac0210c85..4b8b54c7f10 100644
--- a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js
+++ b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js
@@ -21,7 +21,7 @@ var AbstractGreeter = (function () {
 var Greeter = (function (_super) {
     __extends(Greeter, _super);
     function Greeter() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.a = 10;
         _this.nameA = "Ten";
         return _this;
diff --git a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map
index 6b18a783dfa..93070200e18 100644
--- a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map
+++ b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map
@@ -1,2 +1,2 @@
 //// [sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map]
-{"version":3,"file":"sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js","sourceRoot":"","sources":["sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts"],"names":[],"mappings":";;;;;AAAA;IAAA;IACA,CAAC;IAAD,sBAAC;AAAD,CAAC,AADD,IACC;AAED;IAAsB,2BAAe;IAArC;QAAA,kDAGC;QAFU,OAAC,GAAG,EAAE,CAAC;QACP,WAAK,GAAG,KAAK,CAAC;;IACzB,CAAC;IAAD,cAAC;AAAD,CAAC,AAHD,CAAsB,eAAe,GAGpC"}
\ No newline at end of file
+{"version":3,"file":"sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js","sourceRoot":"","sources":["sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts"],"names":[],"mappings":";;;;;AAAA;IAAA;IACA,CAAC;IAAD,sBAAC;AAAD,CAAC,AADD,IACC;AAED;IAAsB,2BAAe;IAArC;QAAA,qEAGC;QAFU,OAAC,GAAG,EAAE,CAAC;QACP,WAAK,GAAG,KAAK,CAAC;;IACzB,CAAC;IAAD,cAAC;AAAD,CAAC,AAHD,CAAsB,eAAe,GAGpC"}
\ No newline at end of file
diff --git a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.sourcemap.txt b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.sourcemap.txt
index 91e284fd063..bc4ff02779f 100644
--- a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.sourcemap.txt
+++ b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.sourcemap.txt
@@ -77,20 +77,20 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
 ---
 >>>    function Greeter() {
 1 >^^^^
-2 >    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
+2 >    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
 1 >Emitted(13, 5) Source(4, 1) + SourceIndex(0)
 ---
->>>        var _this = _super.apply(this, arguments) || this;
+>>>        var _this = _super !== null && _super.apply(this, arguments) || this;
 1->^^^^^^^^
-2 >        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+2 >        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1->
 2 >        class Greeter extends AbstractGreeter {
   >            public a = 10;
   >            public nameA = "Ten";
   >        }
 1->Emitted(14, 9) Source(4, 1) + SourceIndex(0)
-2 >Emitted(14, 59) Source(7, 2) + SourceIndex(0)
+2 >Emitted(14, 78) Source(7, 2) + SourceIndex(0)
 ---
 >>>        _this.a = 10;
 1 >^^^^^^^^
diff --git a/tests/baselines/reference/specializedInheritedConstructors1.js b/tests/baselines/reference/specializedInheritedConstructors1.js
index f65f42941bf..c7940a39dd7 100644
--- a/tests/baselines/reference/specializedInheritedConstructors1.js
+++ b/tests/baselines/reference/specializedInheritedConstructors1.js
@@ -36,7 +36,7 @@ var Model = (function () {
 var MyView = (function (_super) {
     __extends(MyView, _super);
     function MyView() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyView;
 }(View));
diff --git a/tests/baselines/reference/specializedOverloadWithRestParameters.js b/tests/baselines/reference/specializedOverloadWithRestParameters.js
index b76afaff08c..e6e0f0668c0 100644
--- a/tests/baselines/reference/specializedOverloadWithRestParameters.js
+++ b/tests/baselines/reference/specializedOverloadWithRestParameters.js
@@ -27,7 +27,7 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived1.prototype.bar = function () { };
     return Derived1;
diff --git a/tests/baselines/reference/staticFactory1.js b/tests/baselines/reference/staticFactory1.js
index de7588c3ebe..fc52005d8d9 100644
--- a/tests/baselines/reference/staticFactory1.js
+++ b/tests/baselines/reference/staticFactory1.js
@@ -31,7 +31,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Derived.prototype.foo = function () { return 2; };
     return Derived;
diff --git a/tests/baselines/reference/staticInheritance.js b/tests/baselines/reference/staticInheritance.js
index d204c1aed47..aa18468ca89 100644
--- a/tests/baselines/reference/staticInheritance.js
+++ b/tests/baselines/reference/staticInheritance.js
@@ -27,7 +27,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.p1 = doThing(A); // OK
         _this.p2 = doThing(B); // OK
         return _this;
diff --git a/tests/baselines/reference/staticMemberAccessOffDerivedType1.js b/tests/baselines/reference/staticMemberAccessOffDerivedType1.js
index 7b8ca52b9a4..6b4da778d99 100644
--- a/tests/baselines/reference/staticMemberAccessOffDerivedType1.js
+++ b/tests/baselines/reference/staticMemberAccessOffDerivedType1.js
@@ -26,7 +26,7 @@ var SomeBase = (function () {
 var P = (function (_super) {
     __extends(P, _super);
     function P() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return P;
 }(SomeBase));
diff --git a/tests/baselines/reference/staticPropSuper.js b/tests/baselines/reference/staticPropSuper.js
index 6240f8c454f..681f52bd10e 100644
--- a/tests/baselines/reference/staticPropSuper.js
+++ b/tests/baselines/reference/staticPropSuper.js
@@ -49,7 +49,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        var _this;
+        var _this = this;
         var x = 1; // should not error
         _this = _super.call(this) || this;
         return _this;
@@ -60,7 +60,7 @@ B.s = 9;
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        var _this;
+        var _this = this;
         _this.p = 10;
         var x = 1; // should error
         return _this;
@@ -70,7 +70,7 @@ var C = (function (_super) {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         _this.p = 11;
         var x = 1; // should error
         return _this;
@@ -80,7 +80,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        var _this;
+        var _this = this;
         _this.p = 12;
         var x = 1; // should error
         return _this;
diff --git a/tests/baselines/reference/strictModeInConstructor.js b/tests/baselines/reference/strictModeInConstructor.js
index da45bda5c6e..7300e30903b 100644
--- a/tests/baselines/reference/strictModeInConstructor.js
+++ b/tests/baselines/reference/strictModeInConstructor.js
@@ -94,7 +94,7 @@ var C = (function (_super) {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         _this.s = 9;
         var x = 1; // Error
         _this = _super.call(this) || this;
@@ -125,7 +125,7 @@ Cs.s = 9;
 var Ds = (function (_super) {
     __extends(Ds, _super);
     function Ds() {
-        var _this;
+        var _this = this;
         var x = 1; // no Error
         _this = _super.call(this) || this;
         "use strict";
diff --git a/tests/baselines/reference/strictModeReservedWord.js b/tests/baselines/reference/strictModeReservedWord.js
index 29715745890..3b23d890a74 100644
--- a/tests/baselines/reference/strictModeReservedWord.js
+++ b/tests/baselines/reference/strictModeReservedWord.js
@@ -48,7 +48,7 @@ function foo() {
     var myClass = (function (_super) {
         __extends(package, _super);
         function package() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return package;
     }(public));
diff --git a/tests/baselines/reference/strictModeReservedWordInClassDeclaration.js b/tests/baselines/reference/strictModeReservedWordInClassDeclaration.js
index 1507e53d8cf..f920d3dc3e3 100644
--- a/tests/baselines/reference/strictModeReservedWordInClassDeclaration.js
+++ b/tests/baselines/reference/strictModeReservedWordInClassDeclaration.js
@@ -75,14 +75,14 @@ var F1 = (function () {
 var G = (function (_super) {
     __extends(G, _super);
     function G() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return G;
 }(package));
 var H = (function (_super) {
     __extends(H, _super);
     function H() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return H;
 }(package.A));
diff --git a/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.js b/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.js
index b532df7b120..c55450acdeb 100644
--- a/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.js
+++ b/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.js
@@ -55,7 +55,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.bar = function () { return ''; };
     return B;
diff --git a/tests/baselines/reference/subSubClassCanAccessProtectedConstructor.js b/tests/baselines/reference/subSubClassCanAccessProtectedConstructor.js
index 15d6fc70da5..ffffa6ea36f 100644
--- a/tests/baselines/reference/subSubClassCanAccessProtectedConstructor.js
+++ b/tests/baselines/reference/subSubClassCanAccessProtectedConstructor.js
@@ -31,7 +31,7 @@ var Base = (function () {
 var Subclass = (function (_super) {
     __extends(Subclass, _super);
     function Subclass() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.instance1_1 = new Base(); // allowed
         _this.instance1_2 = new Subclass(); // allowed
         return _this;
@@ -41,7 +41,7 @@ var Subclass = (function (_super) {
 var SubclassOfSubclass = (function (_super) {
     __extends(SubclassOfSubclass, _super);
     function SubclassOfSubclass() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.instance2_1 = new Base(); // allowed
         _this.instance2_2 = new Subclass(); // allowed
         _this.instance2_3 = new SubclassOfSubclass(); // allowed
diff --git a/tests/baselines/reference/subtypesOfTypeParameter.js b/tests/baselines/reference/subtypesOfTypeParameter.js
index 38f5b5f1d4b..c2fcc07664d 100644
--- a/tests/baselines/reference/subtypesOfTypeParameter.js
+++ b/tests/baselines/reference/subtypesOfTypeParameter.js
@@ -120,7 +120,7 @@ var C3 = (function () {
 var D1 = (function (_super) {
     __extends(D1, _super);
     function D1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D1;
 }(C3));
diff --git a/tests/baselines/reference/subtypesOfTypeParameterWithConstraints.js b/tests/baselines/reference/subtypesOfTypeParameterWithConstraints.js
index 82bcbf14ecc..73b3bc95fb9 100644
--- a/tests/baselines/reference/subtypesOfTypeParameterWithConstraints.js
+++ b/tests/baselines/reference/subtypesOfTypeParameterWithConstraints.js
@@ -182,28 +182,28 @@ var C3 = (function () {
 var D1 = (function (_super) {
     __extends(D1, _super);
     function D1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D1;
 }(C3));
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(C3));
 var D3 = (function (_super) {
     __extends(D3, _super);
     function D3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D3;
 }(C3));
 var D4 = (function (_super) {
     __extends(D4, _super);
     function D4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D4;
 }(C3));
@@ -213,21 +213,21 @@ var D4 = (function (_super) {
 var D5 = (function (_super) {
     __extends(D5, _super);
     function D5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D5;
 }(C3));
 var D6 = (function (_super) {
     __extends(D6, _super);
     function D6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D6;
 }(C3));
 var D7 = (function (_super) {
     __extends(D7, _super);
     function D7() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D7;
 }(C3));
@@ -236,21 +236,21 @@ var D7 = (function (_super) {
 var D8 = (function (_super) {
     __extends(D8, _super);
     function D8() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D8;
 }(C3));
 var D9 = (function (_super) {
     __extends(D9, _super);
     function D9() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D9;
 }(C3));
 var D10 = (function (_super) {
     __extends(D10, _super);
     function D10() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D10;
 }(C3));
@@ -259,21 +259,21 @@ var D10 = (function (_super) {
 var D11 = (function (_super) {
     __extends(D11, _super);
     function D11() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D11;
 }(C3));
 var D12 = (function (_super) {
     __extends(D12, _super);
     function D12() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D12;
 }(C3));
 var D13 = (function (_super) {
     __extends(D13, _super);
     function D13() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D13;
 }(C3));
@@ -283,28 +283,28 @@ var D13 = (function (_super) {
 var D14 = (function (_super) {
     __extends(D14, _super);
     function D14() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D14;
 }(C3));
 var D15 = (function (_super) {
     __extends(D15, _super);
     function D15() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D15;
 }(C3));
 var D16 = (function (_super) {
     __extends(D16, _super);
     function D16() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D16;
 }(C3));
 var D17 = (function (_super) {
     __extends(D17, _super);
     function D17() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D17;
 }(C3));
@@ -313,28 +313,28 @@ var D17 = (function (_super) {
 var D18 = (function (_super) {
     __extends(D18, _super);
     function D18() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D18;
 }(C3));
 var D19 = (function (_super) {
     __extends(D19, _super);
     function D19() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D19;
 }(C3));
 var D20 = (function (_super) {
     __extends(D20, _super);
     function D20() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D20;
 }(C3));
 var D21 = (function (_super) {
     __extends(D21, _super);
     function D21() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D21;
 }(C3));
@@ -343,28 +343,28 @@ var D21 = (function (_super) {
 var D22 = (function (_super) {
     __extends(D22, _super);
     function D22() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D22;
 }(C3));
 var D23 = (function (_super) {
     __extends(D23, _super);
     function D23() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D23;
 }(C3));
 var D24 = (function (_super) {
     __extends(D24, _super);
     function D24() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D24;
 }(C3));
 var D25 = (function (_super) {
     __extends(D25, _super);
     function D25() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D25;
 }(C3));
@@ -373,28 +373,28 @@ var D25 = (function (_super) {
 var D26 = (function (_super) {
     __extends(D26, _super);
     function D26() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D26;
 }(C3));
 var D27 = (function (_super) {
     __extends(D27, _super);
     function D27() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D27;
 }(C3));
 var D28 = (function (_super) {
     __extends(D28, _super);
     function D28() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D28;
 }(C3));
 var D29 = (function (_super) {
     __extends(D29, _super);
     function D29() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D29;
 }(C3));
diff --git a/tests/baselines/reference/subtypesOfTypeParameterWithConstraints4.js b/tests/baselines/reference/subtypesOfTypeParameterWithConstraints4.js
index e0baced37a4..0f681d9638b 100644
--- a/tests/baselines/reference/subtypesOfTypeParameterWithConstraints4.js
+++ b/tests/baselines/reference/subtypesOfTypeParameterWithConstraints4.js
@@ -118,63 +118,63 @@ var B1 = (function () {
 var D1 = (function (_super) {
     __extends(D1, _super);
     function D1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D1;
 }(B1));
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(B1));
 var D3 = (function (_super) {
     __extends(D3, _super);
     function D3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D3;
 }(B1));
 var D4 = (function (_super) {
     __extends(D4, _super);
     function D4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D4;
 }(B1));
 var D5 = (function (_super) {
     __extends(D5, _super);
     function D5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D5;
 }(B1));
 var D6 = (function (_super) {
     __extends(D6, _super);
     function D6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D6;
 }(B1));
 var D7 = (function (_super) {
     __extends(D7, _super);
     function D7() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D7;
 }(B1));
 var D8 = (function (_super) {
     __extends(D8, _super);
     function D8() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D8;
 }(B1));
 var D9 = (function (_super) {
     __extends(D9, _super);
     function D9() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D9;
 }(B1));
diff --git a/tests/baselines/reference/subtypesOfTypeParameterWithRecursiveConstraints.js b/tests/baselines/reference/subtypesOfTypeParameterWithRecursiveConstraints.js
index 0b17fc07f24..60e1df58d91 100644
--- a/tests/baselines/reference/subtypesOfTypeParameterWithRecursiveConstraints.js
+++ b/tests/baselines/reference/subtypesOfTypeParameterWithRecursiveConstraints.js
@@ -217,63 +217,63 @@ var M1;
     var D1 = (function (_super) {
         __extends(D1, _super);
         function D1() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D1;
     }(Base));
     var D2 = (function (_super) {
         __extends(D2, _super);
         function D2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D2;
     }(Base));
     var D3 = (function (_super) {
         __extends(D3, _super);
         function D3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D3;
     }(Base));
     var D4 = (function (_super) {
         __extends(D4, _super);
         function D4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D4;
     }(Base));
     var D5 = (function (_super) {
         __extends(D5, _super);
         function D5() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D5;
     }(Base));
     var D6 = (function (_super) {
         __extends(D6, _super);
         function D6() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D6;
     }(Base));
     var D7 = (function (_super) {
         __extends(D7, _super);
         function D7() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D7;
     }(Base));
     var D8 = (function (_super) {
         __extends(D8, _super);
         function D8() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D8;
     }(Base));
     var D9 = (function (_super) {
         __extends(D9, _super);
         function D9() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D9;
     }(Base));
@@ -288,63 +288,63 @@ var M2;
     var D1 = (function (_super) {
         __extends(D1, _super);
         function D1() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D1;
     }(Base2));
     var D2 = (function (_super) {
         __extends(D2, _super);
         function D2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D2;
     }(Base2));
     var D3 = (function (_super) {
         __extends(D3, _super);
         function D3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D3;
     }(Base2));
     var D4 = (function (_super) {
         __extends(D4, _super);
         function D4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D4;
     }(Base2));
     var D5 = (function (_super) {
         __extends(D5, _super);
         function D5() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D5;
     }(Base2));
     var D6 = (function (_super) {
         __extends(D6, _super);
         function D6() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D6;
     }(Base2));
     var D7 = (function (_super) {
         __extends(D7, _super);
         function D7() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D7;
     }(Base2));
     var D8 = (function (_super) {
         __extends(D8, _super);
         function D8() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D8;
     }(Base2));
     var D9 = (function (_super) {
         __extends(D9, _super);
         function D9() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return D9;
     }(Base2));
diff --git a/tests/baselines/reference/subtypingTransitivity.js b/tests/baselines/reference/subtypingTransitivity.js
index 9c4c9011758..1693ffc68ef 100644
--- a/tests/baselines/reference/subtypingTransitivity.js
+++ b/tests/baselines/reference/subtypingTransitivity.js
@@ -33,14 +33,14 @@ var B = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(B));
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(B));
diff --git a/tests/baselines/reference/subtypingWithCallSignatures2.js b/tests/baselines/reference/subtypingWithCallSignatures2.js
index 3b5fada2012..1a8e59769f6 100644
--- a/tests/baselines/reference/subtypingWithCallSignatures2.js
+++ b/tests/baselines/reference/subtypingWithCallSignatures2.js
@@ -187,21 +187,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/subtypingWithCallSignatures3.js b/tests/baselines/reference/subtypingWithCallSignatures3.js
index 4ac7d3a7f24..8966c5ff8a7 100644
--- a/tests/baselines/reference/subtypingWithCallSignatures3.js
+++ b/tests/baselines/reference/subtypingWithCallSignatures3.js
@@ -136,21 +136,21 @@ var Errors;
     var Derived = (function (_super) {
         __extends(Derived, _super);
         function Derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived;
     }(Base));
     var Derived2 = (function (_super) {
         __extends(Derived2, _super);
         function Derived2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived2;
     }(Derived));
     var OtherDerived = (function (_super) {
         __extends(OtherDerived, _super);
         function OtherDerived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return OtherDerived;
     }(Base));
diff --git a/tests/baselines/reference/subtypingWithCallSignatures4.js b/tests/baselines/reference/subtypingWithCallSignatures4.js
index 94f549c62c1..f4b414dccf2 100644
--- a/tests/baselines/reference/subtypingWithCallSignatures4.js
+++ b/tests/baselines/reference/subtypingWithCallSignatures4.js
@@ -126,21 +126,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures2.js b/tests/baselines/reference/subtypingWithConstructSignatures2.js
index 1d12aeb945f..da262e26e1a 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures2.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures2.js
@@ -187,21 +187,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures3.js b/tests/baselines/reference/subtypingWithConstructSignatures3.js
index 78582304cb8..c7849ccf9f7 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures3.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures3.js
@@ -138,21 +138,21 @@ var Errors;
     var Derived = (function (_super) {
         __extends(Derived, _super);
         function Derived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived;
     }(Base));
     var Derived2 = (function (_super) {
         __extends(Derived2, _super);
         function Derived2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Derived2;
     }(Derived));
     var OtherDerived = (function (_super) {
         __extends(OtherDerived, _super);
         function OtherDerived() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return OtherDerived;
     }(Base));
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures4.js b/tests/baselines/reference/subtypingWithConstructSignatures4.js
index 17252fdb809..6210c393363 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures4.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures4.js
@@ -126,21 +126,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures5.js b/tests/baselines/reference/subtypingWithConstructSignatures5.js
index a0561606393..717dd1410a3 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures5.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures5.js
@@ -64,21 +64,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures6.js b/tests/baselines/reference/subtypingWithConstructSignatures6.js
index c508781e089..d61d2626f0e 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures6.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures6.js
@@ -67,21 +67,21 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return OtherDerived;
 }(Base));
diff --git a/tests/baselines/reference/subtypingWithNumericIndexer.js b/tests/baselines/reference/subtypingWithNumericIndexer.js
index 3cf75dd83fd..57d1f7044f2 100644
--- a/tests/baselines/reference/subtypingWithNumericIndexer.js
+++ b/tests/baselines/reference/subtypingWithNumericIndexer.js
@@ -54,14 +54,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A));
@@ -75,28 +75,28 @@ var Generics;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
     var B2 = (function (_super) {
         __extends(B2, _super);
         function B2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B2;
     }(A));
     var B3 = (function (_super) {
         __extends(B3, _super);
         function B3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B3;
     }(A));
     var B4 = (function (_super) {
         __extends(B4, _super);
         function B4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B4;
     }(A));
diff --git a/tests/baselines/reference/subtypingWithNumericIndexer3.js b/tests/baselines/reference/subtypingWithNumericIndexer3.js
index e9e8d39bf3c..12e5ad31fb3 100644
--- a/tests/baselines/reference/subtypingWithNumericIndexer3.js
+++ b/tests/baselines/reference/subtypingWithNumericIndexer3.js
@@ -58,14 +58,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A));
@@ -79,35 +79,35 @@ var Generics;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
     var B2 = (function (_super) {
         __extends(B2, _super);
         function B2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B2;
     }(A));
     var B3 = (function (_super) {
         __extends(B3, _super);
         function B3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B3;
     }(A));
     var B4 = (function (_super) {
         __extends(B4, _super);
         function B4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B4;
     }(A));
     var B5 = (function (_super) {
         __extends(B5, _super);
         function B5() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B5;
     }(A));
diff --git a/tests/baselines/reference/subtypingWithNumericIndexer4.js b/tests/baselines/reference/subtypingWithNumericIndexer4.js
index 798e775083f..31ec12fd8ac 100644
--- a/tests/baselines/reference/subtypingWithNumericIndexer4.js
+++ b/tests/baselines/reference/subtypingWithNumericIndexer4.js
@@ -42,7 +42,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -56,14 +56,14 @@ var Generics;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
     var B3 = (function (_super) {
         __extends(B3, _super);
         function B3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B3;
     }(A));
diff --git a/tests/baselines/reference/subtypingWithObjectMembers.js b/tests/baselines/reference/subtypingWithObjectMembers.js
index 3675ed6a410..be8711242d2 100644
--- a/tests/baselines/reference/subtypingWithObjectMembers.js
+++ b/tests/baselines/reference/subtypingWithObjectMembers.js
@@ -81,14 +81,14 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Derived));
@@ -102,7 +102,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -114,7 +114,7 @@ var A2 = (function () {
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A2));
@@ -126,7 +126,7 @@ var A3 = (function () {
 var B3 = (function (_super) {
     __extends(B3, _super);
     function B3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B3;
 }(A3));
@@ -140,7 +140,7 @@ var TwoLevels;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
@@ -152,7 +152,7 @@ var TwoLevels;
     var B2 = (function (_super) {
         __extends(B2, _super);
         function B2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B2;
     }(A2));
@@ -164,7 +164,7 @@ var TwoLevels;
     var B3 = (function (_super) {
         __extends(B3, _super);
         function B3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B3;
     }(A3));
diff --git a/tests/baselines/reference/subtypingWithObjectMembers4.js b/tests/baselines/reference/subtypingWithObjectMembers4.js
index 404b6cbe988..b41750f5e1e 100644
--- a/tests/baselines/reference/subtypingWithObjectMembers4.js
+++ b/tests/baselines/reference/subtypingWithObjectMembers4.js
@@ -48,7 +48,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -60,7 +60,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -72,7 +72,7 @@ var A2 = (function () {
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A2));
@@ -84,7 +84,7 @@ var A3 = (function () {
 var B3 = (function (_super) {
     __extends(B3, _super);
     function B3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B3;
 }(A3));
diff --git a/tests/baselines/reference/subtypingWithObjectMembersAccessibility.js b/tests/baselines/reference/subtypingWithObjectMembersAccessibility.js
index 8b168ea73b5..498fd5f61c3 100644
--- a/tests/baselines/reference/subtypingWithObjectMembersAccessibility.js
+++ b/tests/baselines/reference/subtypingWithObjectMembersAccessibility.js
@@ -48,7 +48,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -60,7 +60,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -72,7 +72,7 @@ var A2 = (function () {
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A2));
@@ -84,7 +84,7 @@ var A3 = (function () {
 var B3 = (function (_super) {
     __extends(B3, _super);
     function B3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B3;
 }(A3));
diff --git a/tests/baselines/reference/subtypingWithObjectMembersAccessibility2.js b/tests/baselines/reference/subtypingWithObjectMembersAccessibility2.js
index 0a83b760218..7092e57d9ed 100644
--- a/tests/baselines/reference/subtypingWithObjectMembersAccessibility2.js
+++ b/tests/baselines/reference/subtypingWithObjectMembersAccessibility2.js
@@ -76,7 +76,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived;
 }(Base));
@@ -90,7 +90,7 @@ var ExplicitPublic;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
@@ -102,7 +102,7 @@ var ExplicitPublic;
     var B2 = (function (_super) {
         __extends(B2, _super);
         function B2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B2;
     }(A2));
@@ -114,7 +114,7 @@ var ExplicitPublic;
     var B3 = (function (_super) {
         __extends(B3, _super);
         function B3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B3;
     }(A3));
@@ -129,7 +129,7 @@ var ImplicitPublic;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
@@ -141,7 +141,7 @@ var ImplicitPublic;
     var B2 = (function (_super) {
         __extends(B2, _super);
         function B2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B2;
     }(A2));
@@ -153,7 +153,7 @@ var ImplicitPublic;
     var B3 = (function (_super) {
         __extends(B3, _super);
         function B3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B3;
     }(A3));
diff --git a/tests/baselines/reference/subtypingWithStringIndexer.js b/tests/baselines/reference/subtypingWithStringIndexer.js
index 195b7d2192e..1e4eae81a95 100644
--- a/tests/baselines/reference/subtypingWithStringIndexer.js
+++ b/tests/baselines/reference/subtypingWithStringIndexer.js
@@ -55,14 +55,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A));
@@ -76,28 +76,28 @@ var Generics;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
     var B2 = (function (_super) {
         __extends(B2, _super);
         function B2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B2;
     }(A));
     var B3 = (function (_super) {
         __extends(B3, _super);
         function B3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B3;
     }(A));
     var B4 = (function (_super) {
         __extends(B4, _super);
         function B4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B4;
     }(A));
diff --git a/tests/baselines/reference/subtypingWithStringIndexer3.js b/tests/baselines/reference/subtypingWithStringIndexer3.js
index 0b2a57324eb..14a3845bc7b 100644
--- a/tests/baselines/reference/subtypingWithStringIndexer3.js
+++ b/tests/baselines/reference/subtypingWithStringIndexer3.js
@@ -58,14 +58,14 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
 var B2 = (function (_super) {
     __extends(B2, _super);
     function B2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B2;
 }(A));
@@ -79,35 +79,35 @@ var Generics;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
     var B2 = (function (_super) {
         __extends(B2, _super);
         function B2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B2;
     }(A));
     var B3 = (function (_super) {
         __extends(B3, _super);
         function B3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B3;
     }(A));
     var B4 = (function (_super) {
         __extends(B4, _super);
         function B4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B4;
     }(A));
     var B5 = (function (_super) {
         __extends(B5, _super);
         function B5() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B5;
     }(A));
diff --git a/tests/baselines/reference/subtypingWithStringIndexer4.js b/tests/baselines/reference/subtypingWithStringIndexer4.js
index 2937261ad05..2573633b6b9 100644
--- a/tests/baselines/reference/subtypingWithStringIndexer4.js
+++ b/tests/baselines/reference/subtypingWithStringIndexer4.js
@@ -42,7 +42,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return B;
 }(A));
@@ -56,14 +56,14 @@ var Generics;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(A));
     var B3 = (function (_super) {
         __extends(B3, _super);
         function B3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B3;
     }(A));
diff --git a/tests/baselines/reference/super.js b/tests/baselines/reference/super.js
index 504e8542d4d..19ceafdfd16 100644
--- a/tests/baselines/reference/super.js
+++ b/tests/baselines/reference/super.js
@@ -58,7 +58,7 @@ var Base = (function () {
 var Sub1 = (function (_super) {
     __extends(Sub1, _super);
     function Sub1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Sub1.prototype.foo = function () {
         return "sub1" + _super.prototype.foo.call(this) + _super.prototype.bar.call(this);
@@ -68,7 +68,7 @@ var Sub1 = (function (_super) {
 var SubSub1 = (function (_super) {
     __extends(SubSub1, _super);
     function SubSub1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     SubSub1.prototype.foo = function () {
         return "subsub1" + _super.prototype.foo.call(this);
diff --git a/tests/baselines/reference/super1.js b/tests/baselines/reference/super1.js
index 0094f696faf..dd34fc105fe 100644
--- a/tests/baselines/reference/super1.js
+++ b/tests/baselines/reference/super1.js
@@ -84,7 +84,7 @@ var Base1 = (function () {
 var Sub1 = (function (_super) {
     __extends(Sub1, _super);
     function Sub1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Sub1.prototype.bar = function () {
         return "base";
@@ -94,7 +94,7 @@ var Sub1 = (function (_super) {
 var SubSub1 = (function (_super) {
     __extends(SubSub1, _super);
     function SubSub1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     SubSub1.prototype.bar = function () {
         return _super.prototype["super"].foo;
@@ -113,7 +113,7 @@ var Base2 = (function () {
 var SubE2 = (function (_super) {
     __extends(SubE2, _super);
     function SubE2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     SubE2.prototype.bar = function () {
         return _super.prototype.prototype.foo = null;
@@ -132,7 +132,7 @@ var Base3 = (function () {
 var SubE3 = (function (_super) {
     __extends(SubE3, _super);
     function SubE3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     SubE3.prototype.bar = function () {
         return _super.prototype.bar.call(this);
@@ -153,7 +153,7 @@ var Base4;
     var SubSub4 = (function (_super) {
         __extends(SubSub4, _super);
         function SubSub4() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         SubSub4.prototype.x = function () {
             return _super.prototype.x.call(this);
diff --git a/tests/baselines/reference/super2.js b/tests/baselines/reference/super2.js
index 1d2331052db..7dc911baa8f 100644
--- a/tests/baselines/reference/super2.js
+++ b/tests/baselines/reference/super2.js
@@ -71,7 +71,7 @@ var Base5 = (function () {
 var Sub5 = (function (_super) {
     __extends(Sub5, _super);
     function Sub5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Sub5.prototype.x = function () {
         return "SubX";
@@ -81,7 +81,7 @@ var Sub5 = (function (_super) {
 var SubSub5 = (function (_super) {
     __extends(SubSub5, _super);
     function SubSub5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     SubSub5.prototype.x = function () {
         return _super.prototype.x.call(this);
@@ -103,7 +103,7 @@ var Base6 = (function () {
 var Sub6 = (function (_super) {
     __extends(Sub6, _super);
     function Sub6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Sub6.prototype.y = function () {
         return "SubY";
@@ -113,7 +113,7 @@ var Sub6 = (function (_super) {
 var SubSub6 = (function (_super) {
     __extends(SubSub6, _super);
     function SubSub6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     SubSub6.prototype.y = function () {
         return _super.prototype.y.call(this);
diff --git a/tests/baselines/reference/superAccess.js b/tests/baselines/reference/superAccess.js
index 0bd9d305d2e..904782fe796 100644
--- a/tests/baselines/reference/superAccess.js
+++ b/tests/baselines/reference/superAccess.js
@@ -30,7 +30,7 @@ MyBase.S1 = 5;
 var MyDerived = (function (_super) {
     __extends(MyDerived, _super);
     function MyDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     MyDerived.prototype.foo = function () {
         var l3 = _super.prototype.S1; // Expected => Error: Only public instance methods of the base class are accessible via the 'super' keyword
diff --git a/tests/baselines/reference/superAccessInFatArrow1.js b/tests/baselines/reference/superAccessInFatArrow1.js
index a7f964309f7..d15b09d85a7 100644
--- a/tests/baselines/reference/superAccessInFatArrow1.js
+++ b/tests/baselines/reference/superAccessInFatArrow1.js
@@ -34,7 +34,7 @@ var test;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         B.prototype.bar = function (callback) {
         };
diff --git a/tests/baselines/reference/superCallAssignResult.js b/tests/baselines/reference/superCallAssignResult.js
index 6e30cc64052..3c34e537b6a 100644
--- a/tests/baselines/reference/superCallAssignResult.js
+++ b/tests/baselines/reference/superCallAssignResult.js
@@ -24,7 +24,7 @@ var E = (function () {
 var H = (function (_super) {
     __extends(H, _super);
     function H() {
-        var _this;
+        var _this = this;
         var x = _this = _super.call(this, 5) || this; // Should be of type void, not E.
         x = 5;
         return _this;
diff --git a/tests/baselines/reference/superCallBeforeThisAccessing3.js b/tests/baselines/reference/superCallBeforeThisAccessing3.js
index 185767fefb6..666ce6f30c1 100644
--- a/tests/baselines/reference/superCallBeforeThisAccessing3.js
+++ b/tests/baselines/reference/superCallBeforeThisAccessing3.js
@@ -27,7 +27,7 @@ var Base = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         var x = function () { _this._t; };
         x(); // no error; we only check super is called before this when the container is a constructor
         _this._t; // error
diff --git a/tests/baselines/reference/superCallBeforeThisAccessing4.js b/tests/baselines/reference/superCallBeforeThisAccessing4.js
index 91acb88ce22..8a3cfd5281a 100644
--- a/tests/baselines/reference/superCallBeforeThisAccessing4.js
+++ b/tests/baselines/reference/superCallBeforeThisAccessing4.js
@@ -24,19 +24,16 @@ var __extends = (this && this.__extends) || function (d, b) {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
-        _this._t;
+        this._t;
         _this = _super.call(this) || this;
-        return _this;
     }
     return D;
 }(null));
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        var _this = _super.call(this) || this;
-        _this._t;
-        return _this;
+        _this = _super.call(this) || this;
+        this._t;
     }
     return E;
 }(null));
diff --git a/tests/baselines/reference/superCallBeforeThisAccessing5.js b/tests/baselines/reference/superCallBeforeThisAccessing5.js
index 57228538faf..3281a3f8b55 100644
--- a/tests/baselines/reference/superCallBeforeThisAccessing5.js
+++ b/tests/baselines/reference/superCallBeforeThisAccessing5.js
@@ -16,9 +16,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
-        _this._t; // No error
-        return _this;
+        this._t; // No error
     }
     return D;
 }(null));
diff --git a/tests/baselines/reference/superCallBeforeThisAccessing7.js b/tests/baselines/reference/superCallBeforeThisAccessing7.js
index 9cfe8736774..9843ef2f588 100644
--- a/tests/baselines/reference/superCallBeforeThisAccessing7.js
+++ b/tests/baselines/reference/superCallBeforeThisAccessing7.js
@@ -27,7 +27,7 @@ var Base = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         var x = {
             j: _this._t
         };
diff --git a/tests/baselines/reference/superCallBeforeThisAccessing8.js b/tests/baselines/reference/superCallBeforeThisAccessing8.js
index fe459b5e031..49b3d9c86c0 100644
--- a/tests/baselines/reference/superCallBeforeThisAccessing8.js
+++ b/tests/baselines/reference/superCallBeforeThisAccessing8.js
@@ -27,7 +27,7 @@ var Base = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         var x = {
             k: _this = _super.call(this, undefined) || this,
             j: _this._t
diff --git a/tests/baselines/reference/superCallInStaticMethod.js b/tests/baselines/reference/superCallInStaticMethod.js
index b31110fdf78..d1d87127e2a 100644
--- a/tests/baselines/reference/superCallInStaticMethod.js
+++ b/tests/baselines/reference/superCallInStaticMethod.js
@@ -62,7 +62,7 @@ var Doing = (function () {
 var Other = (function (_super) {
     __extends(Other, _super);
     function Other() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     // in static method
     Other.staticMethod = function () {
diff --git a/tests/baselines/reference/superCallInsideClassDeclaration.js b/tests/baselines/reference/superCallInsideClassDeclaration.js
index 05e44119608..e472d7ad720 100644
--- a/tests/baselines/reference/superCallInsideClassDeclaration.js
+++ b/tests/baselines/reference/superCallInsideClassDeclaration.js
@@ -35,7 +35,7 @@ var C = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        var _this;
+        var _this = this;
         var D = (function (_super) {
             __extends(D, _super);
             function D() {
diff --git a/tests/baselines/reference/superCallInsideClassExpression.js b/tests/baselines/reference/superCallInsideClassExpression.js
index 3d55fe11cff..6a858c5e6a6 100644
--- a/tests/baselines/reference/superCallInsideClassExpression.js
+++ b/tests/baselines/reference/superCallInsideClassExpression.js
@@ -35,7 +35,7 @@ var C = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        var _this;
+        var _this = this;
         var D = (function (_super) {
             __extends(class_1, _super);
             function class_1() {
diff --git a/tests/baselines/reference/superCallInsideObjectLiteralExpression.js b/tests/baselines/reference/superCallInsideObjectLiteralExpression.js
index 636b03c227f..86782c7114f 100644
--- a/tests/baselines/reference/superCallInsideObjectLiteralExpression.js
+++ b/tests/baselines/reference/superCallInsideObjectLiteralExpression.js
@@ -28,7 +28,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        var _this;
+        var _this = this;
         var x = {
             x: _this = _super.call(this) || this
         };
diff --git a/tests/baselines/reference/superCallWithMissingBaseClass.js b/tests/baselines/reference/superCallWithMissingBaseClass.js
index 16f11088640..b64f990f192 100644
--- a/tests/baselines/reference/superCallWithMissingBaseClass.js
+++ b/tests/baselines/reference/superCallWithMissingBaseClass.js
@@ -18,7 +18,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var Foo = (function (_super) {
     __extends(Foo, _super);
     function Foo() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Foo.prototype.m1 = function () {
         return _super.prototype.m1.call(this);
diff --git a/tests/baselines/reference/superCalls.js b/tests/baselines/reference/superCalls.js
index 99a3b78752c..ed320a81121 100644
--- a/tests/baselines/reference/superCalls.js
+++ b/tests/baselines/reference/superCalls.js
@@ -64,7 +64,7 @@ var OtherBase = (function () {
 var OtherDerived = (function (_super) {
     __extends(OtherDerived, _super);
     function OtherDerived() {
-        var _this;
+        var _this = this;
         var p = '';
         _this = _super.call(this) || this;
         return _this;
diff --git a/tests/baselines/reference/superCallsInConstructor.js b/tests/baselines/reference/superCallsInConstructor.js
index 48b79acadf4..eb6ef0dbbdc 100644
--- a/tests/baselines/reference/superCallsInConstructor.js
+++ b/tests/baselines/reference/superCallsInConstructor.js
@@ -41,7 +41,7 @@ var Base = (function () {
 var Derived = (function (_super) {
     __extends(Derived, _super);
     function Derived() {
-        var _this;
+        var _this = this;
         with (new C()) {
             foo();
             _this = _super.call(this) || this;
diff --git a/tests/baselines/reference/superInCatchBlock1.js b/tests/baselines/reference/superInCatchBlock1.js
index e1fc0f97024..c1e8e7c0f4d 100644
--- a/tests/baselines/reference/superInCatchBlock1.js
+++ b/tests/baselines/reference/superInCatchBlock1.js
@@ -28,7 +28,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.m = function () {
         try {
diff --git a/tests/baselines/reference/superInConstructorParam1.js b/tests/baselines/reference/superInConstructorParam1.js
index 8c99b649917..0f5b6ae72c9 100644
--- a/tests/baselines/reference/superInConstructorParam1.js
+++ b/tests/baselines/reference/superInConstructorParam1.js
@@ -28,7 +28,7 @@ var C = (function (_super) {
     __extends(C, _super);
     function C(a) {
         if (a === void 0) { a = _super.foo.call(_this); }
-        var _this;
+        var _this = this;
         return _this;
     }
     return C;
diff --git a/tests/baselines/reference/superInObjectLiterals_ES5.js b/tests/baselines/reference/superInObjectLiterals_ES5.js
index 816277e4e9e..9eed965ea17 100644
--- a/tests/baselines/reference/superInObjectLiterals_ES5.js
+++ b/tests/baselines/reference/superInObjectLiterals_ES5.js
@@ -100,7 +100,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.f = function () {
         var _this = this;
diff --git a/tests/baselines/reference/superNewCall1.js b/tests/baselines/reference/superNewCall1.js
index 30b07308bb2..fa2425ffd45 100644
--- a/tests/baselines/reference/superNewCall1.js
+++ b/tests/baselines/reference/superNewCall1.js
@@ -27,7 +27,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        var _this;
+        var _this = this;
         new _super.prototype(function (value) { return String(value); });
         return _this;
     }
diff --git a/tests/baselines/reference/superPropertyAccess.js b/tests/baselines/reference/superPropertyAccess.js
index 7b5823e598b..a6496af6ad1 100644
--- a/tests/baselines/reference/superPropertyAccess.js
+++ b/tests/baselines/reference/superPropertyAccess.js
@@ -61,7 +61,7 @@ var MyBase = (function () {
 var MyDerived = (function (_super) {
     __extends(MyDerived, _super);
     function MyDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     MyDerived.prototype.foo = function () {
         _super.prototype.m1.call(this, "hi"); // Should be allowed, method on base prototype
diff --git a/tests/baselines/reference/superPropertyAccessInComputedPropertiesOfNestedType_ES5.js b/tests/baselines/reference/superPropertyAccessInComputedPropertiesOfNestedType_ES5.js
index 956bce4ef2e..5647ecc7c59 100644
--- a/tests/baselines/reference/superPropertyAccessInComputedPropertiesOfNestedType_ES5.js
+++ b/tests/baselines/reference/superPropertyAccessInComputedPropertiesOfNestedType_ES5.js
@@ -29,7 +29,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     B.prototype.foo = function () { return 2; };
     B.prototype.bar = function () {
diff --git a/tests/baselines/reference/superPropertyAccess_ES5.js b/tests/baselines/reference/superPropertyAccess_ES5.js
index 45c32076be9..20b39d3951c 100644
--- a/tests/baselines/reference/superPropertyAccess_ES5.js
+++ b/tests/baselines/reference/superPropertyAccess_ES5.js
@@ -72,7 +72,7 @@ var A = (function () {
 var B = (function (_super) {
     __extends(B, _super);
     function B() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Object.defineProperty(B.prototype, "property", {
         set: function (value) {
diff --git a/tests/baselines/reference/superPropertyInConstructorBeforeSuperCall.js b/tests/baselines/reference/superPropertyInConstructorBeforeSuperCall.js
index 3fcf7167ee5..a0ef21b93c4 100644
--- a/tests/baselines/reference/superPropertyInConstructorBeforeSuperCall.js
+++ b/tests/baselines/reference/superPropertyInConstructorBeforeSuperCall.js
@@ -30,7 +30,7 @@ var B = (function () {
 var C1 = (function (_super) {
     __extends(C1, _super);
     function C1() {
-        var _this;
+        var _this = this;
         _super.prototype.x.call(_this);
         _this = _super.call(this) || this;
         return _this;
diff --git a/tests/baselines/reference/superSymbolIndexedAccess5.js b/tests/baselines/reference/superSymbolIndexedAccess5.js
index dd37deb5af3..b4eeb79d8ea 100644
--- a/tests/baselines/reference/superSymbolIndexedAccess5.js
+++ b/tests/baselines/reference/superSymbolIndexedAccess5.js
@@ -31,7 +31,7 @@ var Foo = (function () {
 var Bar = (function (_super) {
     __extends(Bar, _super);
     function Bar() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Bar.prototype[symbol] = function () {
         return _super.prototype[symbol].call(this);
diff --git a/tests/baselines/reference/superSymbolIndexedAccess6.js b/tests/baselines/reference/superSymbolIndexedAccess6.js
index 8c8534b428a..5f5e53015e9 100644
--- a/tests/baselines/reference/superSymbolIndexedAccess6.js
+++ b/tests/baselines/reference/superSymbolIndexedAccess6.js
@@ -31,7 +31,7 @@ var Foo = (function () {
 var Bar = (function (_super) {
     __extends(Bar, _super);
     function Bar() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Bar[symbol] = function () {
         return _super[symbol].call(this);
diff --git a/tests/baselines/reference/superWithTypeArgument.js b/tests/baselines/reference/superWithTypeArgument.js
index a1c04975404..f47fbb716f4 100644
--- a/tests/baselines/reference/superWithTypeArgument.js
+++ b/tests/baselines/reference/superWithTypeArgument.js
@@ -23,7 +23,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         _super.prototype..call(_this);
         return _this;
     }
diff --git a/tests/baselines/reference/superWithTypeArgument2.js b/tests/baselines/reference/superWithTypeArgument2.js
index 42a0e46d4c0..952889810e2 100644
--- a/tests/baselines/reference/superWithTypeArgument2.js
+++ b/tests/baselines/reference/superWithTypeArgument2.js
@@ -23,7 +23,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D(x) {
-        var _this;
+        var _this = this;
         _super.prototype..call(_this, x);
         return _this;
     }
diff --git a/tests/baselines/reference/superWithTypeArgument3.js b/tests/baselines/reference/superWithTypeArgument3.js
index 803e5c264c2..ecf2fa0892f 100644
--- a/tests/baselines/reference/superWithTypeArgument3.js
+++ b/tests/baselines/reference/superWithTypeArgument3.js
@@ -28,7 +28,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         _super.prototype..call(_this);
         return _this;
     }
diff --git a/tests/baselines/reference/super_inside-object-literal-getters-and-setters.js b/tests/baselines/reference/super_inside-object-literal-getters-and-setters.js
index 6815b71ce11..7c16ce42740 100644
--- a/tests/baselines/reference/super_inside-object-literal-getters-and-setters.js
+++ b/tests/baselines/reference/super_inside-object-literal-getters-and-setters.js
@@ -57,7 +57,7 @@ var F = (function () {
 var SuperObjectTest = (function (_super) {
     __extends(SuperObjectTest, _super);
     function SuperObjectTest() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     SuperObjectTest.prototype.testing = function () {
         var test = {
diff --git a/tests/baselines/reference/switchStatements.js b/tests/baselines/reference/switchStatements.js
index 2e1aecc7288..d244345a00c 100644
--- a/tests/baselines/reference/switchStatements.js
+++ b/tests/baselines/reference/switchStatements.js
@@ -98,7 +98,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
diff --git a/tests/baselines/reference/systemModuleWithSuperClass.js b/tests/baselines/reference/systemModuleWithSuperClass.js
index 78c09355fa0..79c435806f8 100644
--- a/tests/baselines/reference/systemModuleWithSuperClass.js
+++ b/tests/baselines/reference/systemModuleWithSuperClass.js
@@ -49,7 +49,7 @@ System.register(["./foo"], function (exports_1, context_1) {
             Bar = (function (_super) {
                 __extends(Bar, _super);
                 function Bar() {
-                    return _super.apply(this, arguments) || this;
+                    return _super !== null && _super.apply(this, arguments) || this;
                 }
                 return Bar;
             }(foo_1.Foo));
diff --git a/tests/baselines/reference/thisInInvalidContexts.js b/tests/baselines/reference/thisInInvalidContexts.js
index 7f299fd7e10..178332d5d21 100644
--- a/tests/baselines/reference/thisInInvalidContexts.js
+++ b/tests/baselines/reference/thisInInvalidContexts.js
@@ -98,7 +98,7 @@ genericFunc(undefined); // Should be an error
 var ErrClass3 = (function (_super) {
     __extends(ErrClass3, _super);
     function ErrClass3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ErrClass3;
 }(this));
diff --git a/tests/baselines/reference/thisInInvalidContextsExternalModule.js b/tests/baselines/reference/thisInInvalidContextsExternalModule.js
index 65a1ef1eee9..6681316822e 100644
--- a/tests/baselines/reference/thisInInvalidContextsExternalModule.js
+++ b/tests/baselines/reference/thisInInvalidContextsExternalModule.js
@@ -99,7 +99,7 @@ genericFunc(undefined); // Should be an error
 var ErrClass3 = (function (_super) {
     __extends(ErrClass3, _super);
     function ErrClass3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return ErrClass3;
 }(this));
diff --git a/tests/baselines/reference/thisTypeInFunctions.js b/tests/baselines/reference/thisTypeInFunctions.js
index 6400f410a09..9400cbcad07 100644
--- a/tests/baselines/reference/thisTypeInFunctions.js
+++ b/tests/baselines/reference/thisTypeInFunctions.js
@@ -227,7 +227,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D;
 }(C));
@@ -336,7 +336,7 @@ var Base1 = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived1;
 }(Base1));
@@ -350,7 +350,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/thisTypeInFunctionsNegative.js b/tests/baselines/reference/thisTypeInFunctionsNegative.js
index 446bc15e6d9..7e40bac38bc 100644
--- a/tests/baselines/reference/thisTypeInFunctionsNegative.js
+++ b/tests/baselines/reference/thisTypeInFunctionsNegative.js
@@ -296,7 +296,7 @@ var Base1 = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived1;
 }(Base1));
@@ -310,7 +310,7 @@ var Base2 = (function () {
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base2));
diff --git a/tests/baselines/reference/tsxCorrectlyParseLessThanComparison1.js b/tests/baselines/reference/tsxCorrectlyParseLessThanComparison1.js
index f5d35ccaf77..9712e775482 100644
--- a/tests/baselines/reference/tsxCorrectlyParseLessThanComparison1.js
+++ b/tests/baselines/reference/tsxCorrectlyParseLessThanComparison1.js
@@ -29,7 +29,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var ShortDetails = (function (_super) {
     __extends(ShortDetails, _super);
     function ShortDetails() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     ShortDetails.prototype.render = function () {
         if (this.props.id < 1) {
diff --git a/tests/baselines/reference/tsxDynamicTagName5.js b/tests/baselines/reference/tsxDynamicTagName5.js
index d3bb404ceea..69355b62f0a 100644
--- a/tests/baselines/reference/tsxDynamicTagName5.js
+++ b/tests/baselines/reference/tsxDynamicTagName5.js
@@ -30,7 +30,7 @@ var React = require("react");
 var Text = (function (_super) {
     __extends(Text, _super);
     function Text() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this._tagName = 'div';
         return _this;
     }
diff --git a/tests/baselines/reference/tsxDynamicTagName7.js b/tests/baselines/reference/tsxDynamicTagName7.js
index 84debfd3e71..30815feac9f 100644
--- a/tests/baselines/reference/tsxDynamicTagName7.js
+++ b/tests/baselines/reference/tsxDynamicTagName7.js
@@ -30,7 +30,7 @@ var React = require("react");
 var Text = (function (_super) {
     __extends(Text, _super);
     function Text() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this._tagName = 'div';
         return _this;
     }
diff --git a/tests/baselines/reference/tsxDynamicTagName8.js b/tests/baselines/reference/tsxDynamicTagName8.js
index 6166b99f4ac..3e3a483b124 100644
--- a/tests/baselines/reference/tsxDynamicTagName8.js
+++ b/tests/baselines/reference/tsxDynamicTagName8.js
@@ -30,7 +30,7 @@ var React = require("react");
 var Text = (function (_super) {
     __extends(Text, _super);
     function Text() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this._tagName = 'div';
         return _this;
     }
diff --git a/tests/baselines/reference/tsxDynamicTagName9.js b/tests/baselines/reference/tsxDynamicTagName9.js
index 928649264c8..c8c2c65baa9 100644
--- a/tests/baselines/reference/tsxDynamicTagName9.js
+++ b/tests/baselines/reference/tsxDynamicTagName9.js
@@ -30,7 +30,7 @@ var React = require("react");
 var Text = (function (_super) {
     __extends(Text, _super);
     function Text() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this._tagName = 'div';
         return _this;
     }
diff --git a/tests/baselines/reference/tsxExternalModuleEmit1.js b/tests/baselines/reference/tsxExternalModuleEmit1.js
index 58e7f1c8d85..ead6ef040f2 100644
--- a/tests/baselines/reference/tsxExternalModuleEmit1.js
+++ b/tests/baselines/reference/tsxExternalModuleEmit1.js
@@ -42,7 +42,7 @@ var React = require("react");
 var Button = (function (_super) {
     __extends(Button, _super);
     function Button() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     Button.prototype.render = function () {
         return <button>Some button</button>;
@@ -63,7 +63,7 @@ var button_1 = require("./button");
 var App = (function (_super) {
     __extends(App, _super);
     function App() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     App.prototype.render = function () {
         return <button_1.Button />;
diff --git a/tests/baselines/reference/tsxStatelessFunctionComponents2.js b/tests/baselines/reference/tsxStatelessFunctionComponents2.js
index 88d91723501..7c839bee4f4 100644
--- a/tests/baselines/reference/tsxStatelessFunctionComponents2.js
+++ b/tests/baselines/reference/tsxStatelessFunctionComponents2.js
@@ -52,7 +52,7 @@ function Greet(x) {
 var BigGreeter = (function (_super) {
     __extends(BigGreeter, _super);
     function BigGreeter() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     BigGreeter.prototype.render = function () {
         return <div></div>;
diff --git a/tests/baselines/reference/tsxUnionTypeComponent1.js b/tests/baselines/reference/tsxUnionTypeComponent1.js
index 3520b5af372..66a6cae8787 100644
--- a/tests/baselines/reference/tsxUnionTypeComponent1.js
+++ b/tests/baselines/reference/tsxUnionTypeComponent1.js
@@ -35,7 +35,7 @@ var React = require("react");
 var MyComponent = (function (_super) {
     __extends(MyComponent, _super);
     function MyComponent() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     MyComponent.prototype.render = function () {
         var AnyComponent = this.props.AnyComponent;
@@ -49,7 +49,7 @@ React.createElement(MyComponent, { AnyComponent: function () { return React.crea
 var MyButtonComponent = (function (_super) {
     __extends(MyButtonComponent, _super);
     function MyButtonComponent() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return MyButtonComponent;
 }(React.Component));
diff --git a/tests/baselines/reference/typeAssertions.js b/tests/baselines/reference/typeAssertions.js
index a57fb222a77..062b79ef436 100644
--- a/tests/baselines/reference/typeAssertions.js
+++ b/tests/baselines/reference/typeAssertions.js
@@ -74,7 +74,7 @@ var SomeBase = (function () {
 var SomeDerived = (function (_super) {
     __extends(SomeDerived, _super);
     function SomeDerived() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return SomeDerived;
 }(SomeBase));
diff --git a/tests/baselines/reference/typeGuardFunction.js b/tests/baselines/reference/typeGuardFunction.js
index b88d1038969..675d4dd6d86 100644
--- a/tests/baselines/reference/typeGuardFunction.js
+++ b/tests/baselines/reference/typeGuardFunction.js
@@ -102,7 +102,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/typeGuardFunctionErrors.js b/tests/baselines/reference/typeGuardFunctionErrors.js
index 99c25faaa88..14a58e37133 100644
--- a/tests/baselines/reference/typeGuardFunctionErrors.js
+++ b/tests/baselines/reference/typeGuardFunctionErrors.js
@@ -164,7 +164,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/typeGuardFunctionGenerics.js b/tests/baselines/reference/typeGuardFunctionGenerics.js
index 703c809274f..058b3068f8b 100644
--- a/tests/baselines/reference/typeGuardFunctionGenerics.js
+++ b/tests/baselines/reference/typeGuardFunctionGenerics.js
@@ -52,7 +52,7 @@ var B = (function () {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(A));
diff --git a/tests/baselines/reference/typeGuardFunctionOfFormThis.js b/tests/baselines/reference/typeGuardFunctionOfFormThis.js
index c052ea7d72b..a4fa26fa058 100644
--- a/tests/baselines/reference/typeGuardFunctionOfFormThis.js
+++ b/tests/baselines/reference/typeGuardFunctionOfFormThis.js
@@ -161,7 +161,7 @@ var RoyalGuard = (function () {
 var LeadGuard = (function (_super) {
     __extends(LeadGuard, _super);
     function LeadGuard() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     LeadGuard.prototype.lead = function () { };
     ;
@@ -170,7 +170,7 @@ var LeadGuard = (function (_super) {
 var FollowerGuard = (function (_super) {
     __extends(FollowerGuard, _super);
     function FollowerGuard() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     FollowerGuard.prototype.follow = function () { };
     ;
@@ -224,7 +224,7 @@ var ArrowGuard = (function () {
 var ArrowElite = (function (_super) {
     __extends(ArrowElite, _super);
     function ArrowElite() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     ArrowElite.prototype.defend = function () { };
     return ArrowElite;
@@ -232,7 +232,7 @@ var ArrowElite = (function (_super) {
 var ArrowMedic = (function (_super) {
     __extends(ArrowMedic, _super);
     function ArrowMedic() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     ArrowMedic.prototype.heal = function () { };
     return ArrowMedic;
@@ -266,7 +266,7 @@ var MimicGuard = (function () {
 var MimicLeader = (function (_super) {
     __extends(MimicLeader, _super);
     function MimicLeader() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     MimicLeader.prototype.lead = function () { };
     return MimicLeader;
@@ -274,7 +274,7 @@ var MimicLeader = (function (_super) {
 var MimicFollower = (function (_super) {
     __extends(MimicFollower, _super);
     function MimicFollower() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     MimicFollower.prototype.follow = function () { };
     return MimicFollower;
diff --git a/tests/baselines/reference/typeGuardFunctionOfFormThisErrors.js b/tests/baselines/reference/typeGuardFunctionOfFormThisErrors.js
index a85a207a665..1d71f90525b 100644
--- a/tests/baselines/reference/typeGuardFunctionOfFormThisErrors.js
+++ b/tests/baselines/reference/typeGuardFunctionOfFormThisErrors.js
@@ -79,7 +79,7 @@ var RoyalGuard = (function () {
 var LeadGuard = (function (_super) {
     __extends(LeadGuard, _super);
     function LeadGuard() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     LeadGuard.prototype.lead = function () { };
     ;
@@ -88,7 +88,7 @@ var LeadGuard = (function (_super) {
 var FollowerGuard = (function (_super) {
     __extends(FollowerGuard, _super);
     function FollowerGuard() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     FollowerGuard.prototype.follow = function () { };
     ;
diff --git a/tests/baselines/reference/typeGuardOfFormInstanceOf.js b/tests/baselines/reference/typeGuardOfFormInstanceOf.js
index a181a446a81..ec1a455ed23 100644
--- a/tests/baselines/reference/typeGuardOfFormInstanceOf.js
+++ b/tests/baselines/reference/typeGuardOfFormInstanceOf.js
@@ -91,7 +91,7 @@ var C2 = (function () {
 var D1 = (function (_super) {
     __extends(D1, _super);
     function D1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D1;
 }(C1));
diff --git a/tests/baselines/reference/typeGuardOfFormIsType.js b/tests/baselines/reference/typeGuardOfFormIsType.js
index 14e9259a9e7..537f203bc2c 100644
--- a/tests/baselines/reference/typeGuardOfFormIsType.js
+++ b/tests/baselines/reference/typeGuardOfFormIsType.js
@@ -56,7 +56,7 @@ var C2 = (function () {
 var D1 = (function (_super) {
     __extends(D1, _super);
     function D1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D1;
 }(C1));
diff --git a/tests/baselines/reference/typeGuardOfFormThisMember.js b/tests/baselines/reference/typeGuardOfFormThisMember.js
index 52097af34f7..dcd3fd8e6bb 100644
--- a/tests/baselines/reference/typeGuardOfFormThisMember.js
+++ b/tests/baselines/reference/typeGuardOfFormThisMember.js
@@ -128,7 +128,7 @@ var Test;
     var Directory = (function (_super) {
         __extends(Directory, _super);
         function Directory() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Directory;
     }(FileSystemObject));
diff --git a/tests/baselines/reference/typeGuardOfFormThisMemberErrors.js b/tests/baselines/reference/typeGuardOfFormThisMemberErrors.js
index c65445a3a5a..0f7379acfb8 100644
--- a/tests/baselines/reference/typeGuardOfFormThisMemberErrors.js
+++ b/tests/baselines/reference/typeGuardOfFormThisMemberErrors.js
@@ -78,7 +78,7 @@ var Test;
     var Directory = (function (_super) {
         __extends(Directory, _super);
         function Directory() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return Directory;
     }(FileSystemObject));
diff --git a/tests/baselines/reference/typeMatch2.js b/tests/baselines/reference/typeMatch2.js
index 2cae93924bc..921729686c4 100644
--- a/tests/baselines/reference/typeMatch2.js
+++ b/tests/baselines/reference/typeMatch2.js
@@ -65,7 +65,7 @@ var Animal = (function () {
 var Giraffe = (function (_super) {
     __extends(Giraffe, _super);
     function Giraffe() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Giraffe;
 }(Animal));
diff --git a/tests/baselines/reference/typeOfSuperCall.js b/tests/baselines/reference/typeOfSuperCall.js
index 179e981b8d1..4f67778694a 100644
--- a/tests/baselines/reference/typeOfSuperCall.js
+++ b/tests/baselines/reference/typeOfSuperCall.js
@@ -22,7 +22,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         var x = _this = _super.call(this) || this;
         return _this;
     }
diff --git a/tests/baselines/reference/typeParameterAsBaseClass.js b/tests/baselines/reference/typeParameterAsBaseClass.js
index 15d1c3b396e..7130c7bd4fc 100644
--- a/tests/baselines/reference/typeParameterAsBaseClass.js
+++ b/tests/baselines/reference/typeParameterAsBaseClass.js
@@ -11,7 +11,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(T));
diff --git a/tests/baselines/reference/typeParameterAsBaseType.js b/tests/baselines/reference/typeParameterAsBaseType.js
index 2d0962f01d7..1d4335b1afb 100644
--- a/tests/baselines/reference/typeParameterAsBaseType.js
+++ b/tests/baselines/reference/typeParameterAsBaseType.js
@@ -21,14 +21,14 @@ var __extends = (this && this.__extends) || function (d, b) {
 var C = (function (_super) {
     __extends(C, _super);
     function C() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C;
 }(T));
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(U));
diff --git a/tests/baselines/reference/typeParameterExtendingUnion1.js b/tests/baselines/reference/typeParameterExtendingUnion1.js
index 2738aa20528..4f9be559179 100644
--- a/tests/baselines/reference/typeParameterExtendingUnion1.js
+++ b/tests/baselines/reference/typeParameterExtendingUnion1.js
@@ -27,14 +27,14 @@ var Animal = (function () {
 var Cat = (function (_super) {
     __extends(Cat, _super);
     function Cat() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Cat;
 }(Animal));
 var Dog = (function (_super) {
     __extends(Dog, _super);
     function Dog() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Dog;
 }(Animal));
diff --git a/tests/baselines/reference/typeParameterExtendingUnion2.js b/tests/baselines/reference/typeParameterExtendingUnion2.js
index b3754436f26..cf10d82f8d9 100644
--- a/tests/baselines/reference/typeParameterExtendingUnion2.js
+++ b/tests/baselines/reference/typeParameterExtendingUnion2.js
@@ -27,14 +27,14 @@ var Animal = (function () {
 var Cat = (function (_super) {
     __extends(Cat, _super);
     function Cat() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Cat;
 }(Animal));
 var Dog = (function (_super) {
     __extends(Dog, _super);
     function Dog() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Dog;
 }(Animal));
diff --git a/tests/baselines/reference/typeRelationships.js b/tests/baselines/reference/typeRelationships.js
index 2f97f4b0d1c..366b7a766db 100644
--- a/tests/baselines/reference/typeRelationships.js
+++ b/tests/baselines/reference/typeRelationships.js
@@ -72,7 +72,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this = _super.apply(this, arguments) || this;
+        var _this = _super !== null && _super.apply(this, arguments) || this;
         _this.self1 = _this;
         _this.self2 = _this.self;
         _this.self3 = _this.foo();
diff --git a/tests/baselines/reference/typeValueConflict1.js b/tests/baselines/reference/typeValueConflict1.js
index 8711a656bf5..bfdb4f18b89 100644
--- a/tests/baselines/reference/typeValueConflict1.js
+++ b/tests/baselines/reference/typeValueConflict1.js
@@ -33,7 +33,7 @@ var M2;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(M1.A));
diff --git a/tests/baselines/reference/typeValueConflict2.js b/tests/baselines/reference/typeValueConflict2.js
index 7abda8110b6..b80de751228 100644
--- a/tests/baselines/reference/typeValueConflict2.js
+++ b/tests/baselines/reference/typeValueConflict2.js
@@ -40,7 +40,7 @@ var M2;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(M1.A));
@@ -51,7 +51,7 @@ var M3;
     var B = (function (_super) {
         __extends(B, _super);
         function B() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return B;
     }(M1.A));
diff --git a/tests/baselines/reference/typeofClass2.js b/tests/baselines/reference/typeofClass2.js
index f1ec6a77b14..107fd03e314 100644
--- a/tests/baselines/reference/typeofClass2.js
+++ b/tests/baselines/reference/typeofClass2.js
@@ -37,7 +37,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.baz = function (x) { };
     D.prototype.foo = function () { };
diff --git a/tests/baselines/reference/typesWithSpecializedCallSignatures.js b/tests/baselines/reference/typesWithSpecializedCallSignatures.js
index 045f7b40e55..8af2584f45a 100644
--- a/tests/baselines/reference/typesWithSpecializedCallSignatures.js
+++ b/tests/baselines/reference/typesWithSpecializedCallSignatures.js
@@ -56,14 +56,14 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived1;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/typesWithSpecializedConstructSignatures.js b/tests/baselines/reference/typesWithSpecializedConstructSignatures.js
index b4d42d819ed..25d6d68e41b 100644
--- a/tests/baselines/reference/typesWithSpecializedConstructSignatures.js
+++ b/tests/baselines/reference/typesWithSpecializedConstructSignatures.js
@@ -54,14 +54,14 @@ var Base = (function () {
 var Derived1 = (function (_super) {
     __extends(Derived1, _super);
     function Derived1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived1;
 }(Base));
 var Derived2 = (function (_super) {
     __extends(Derived2, _super);
     function Derived2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return Derived2;
 }(Base));
diff --git a/tests/baselines/reference/undeclaredBase.js b/tests/baselines/reference/undeclaredBase.js
index 4b7813231cf..2c84db97a7a 100644
--- a/tests/baselines/reference/undeclaredBase.js
+++ b/tests/baselines/reference/undeclaredBase.js
@@ -14,7 +14,7 @@ var M;
     var C = (function (_super) {
         __extends(C, _super);
         function C() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return C;
     }(M.I));
diff --git a/tests/baselines/reference/undefinedIsSubtypeOfEverything.js b/tests/baselines/reference/undefinedIsSubtypeOfEverything.js
index 7e480d18a0a..3e14230fba3 100644
--- a/tests/baselines/reference/undefinedIsSubtypeOfEverything.js
+++ b/tests/baselines/reference/undefinedIsSubtypeOfEverything.js
@@ -136,105 +136,105 @@ var Base = (function () {
 var D0 = (function (_super) {
     __extends(D0, _super);
     function D0() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D0;
 }(Base));
 var DA = (function (_super) {
     __extends(DA, _super);
     function DA() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return DA;
 }(Base));
 var D1 = (function (_super) {
     __extends(D1, _super);
     function D1() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D1;
 }(Base));
 var D1A = (function (_super) {
     __extends(D1A, _super);
     function D1A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D1A;
 }(Base));
 var D2 = (function (_super) {
     __extends(D2, _super);
     function D2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2;
 }(Base));
 var D2A = (function (_super) {
     __extends(D2A, _super);
     function D2A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D2A;
 }(Base));
 var D3 = (function (_super) {
     __extends(D3, _super);
     function D3() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D3;
 }(Base));
 var D3A = (function (_super) {
     __extends(D3A, _super);
     function D3A() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D3A;
 }(Base));
 var D4 = (function (_super) {
     __extends(D4, _super);
     function D4() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D4;
 }(Base));
 var D5 = (function (_super) {
     __extends(D5, _super);
     function D5() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D5;
 }(Base));
 var D6 = (function (_super) {
     __extends(D6, _super);
     function D6() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D6;
 }(Base));
 var D7 = (function (_super) {
     __extends(D7, _super);
     function D7() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D7;
 }(Base));
 var D8 = (function (_super) {
     __extends(D8, _super);
     function D8() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D8;
 }(Base));
 var D9 = (function (_super) {
     __extends(D9, _super);
     function D9() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D9;
 }(Base));
 var D10 = (function (_super) {
     __extends(D10, _super);
     function D10() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D10;
 }(Base));
@@ -245,7 +245,7 @@ var E;
 var D11 = (function (_super) {
     __extends(D11, _super);
     function D11() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D11;
 }(Base));
@@ -256,7 +256,7 @@ function f() { }
 var D12 = (function (_super) {
     __extends(D12, _super);
     function D12() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D12;
 }(Base));
@@ -271,21 +271,21 @@ var c = (function () {
 var D13 = (function (_super) {
     __extends(D13, _super);
     function D13() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D13;
 }(Base));
 var D14 = (function (_super) {
     __extends(D14, _super);
     function D14() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D14;
 }(Base));
 var D15 = (function (_super) {
     __extends(D15, _super);
     function D15() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D15;
 }(Base));
@@ -295,14 +295,14 @@ var D15 = (function (_super) {
 var D16 = (function (_super) {
     __extends(D16, _super);
     function D16() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D16;
 }(Base));
 var D17 = (function (_super) {
     __extends(D17, _super);
     function D17() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return D17;
 }(Base));
diff --git a/tests/baselines/reference/underscoreMapFirst.js b/tests/baselines/reference/underscoreMapFirst.js
index c8e936af527..17f2ffb035c 100644
--- a/tests/baselines/reference/underscoreMapFirst.js
+++ b/tests/baselines/reference/underscoreMapFirst.js
@@ -57,7 +57,7 @@ var __extends = (this && this.__extends) || function (d, b) {
 var MyView = (function (_super) {
     __extends(MyView, _super);
     function MyView() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     MyView.prototype.getDataSeries = function () {
         var data = this.model.get("data");
diff --git a/tests/baselines/reference/underscoreThisInDerivedClass01.js b/tests/baselines/reference/underscoreThisInDerivedClass01.js
index 000176c213f..7b3c9e0aea5 100644
--- a/tests/baselines/reference/underscoreThisInDerivedClass01.js
+++ b/tests/baselines/reference/underscoreThisInDerivedClass01.js
@@ -47,7 +47,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         var _this = "uh-oh?";
         _this = _super.call(this) || this;
         return _this;
diff --git a/tests/baselines/reference/underscoreThisInDerivedClass02.js b/tests/baselines/reference/underscoreThisInDerivedClass02.js
index c1e9494376b..28a4f91d871 100644
--- a/tests/baselines/reference/underscoreThisInDerivedClass02.js
+++ b/tests/baselines/reference/underscoreThisInDerivedClass02.js
@@ -36,7 +36,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        var _this;
+        var _this = this;
         var _this = "uh-oh?";
         return _this;
     }
diff --git a/tests/baselines/reference/unionTypeEquivalence.js b/tests/baselines/reference/unionTypeEquivalence.js
index e4d0acc893c..4464b8e6ede 100644
--- a/tests/baselines/reference/unionTypeEquivalence.js
+++ b/tests/baselines/reference/unionTypeEquivalence.js
@@ -34,7 +34,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.foo = function () { };
     return D;
diff --git a/tests/baselines/reference/unionTypeFromArrayLiteral.js b/tests/baselines/reference/unionTypeFromArrayLiteral.js
index 83ad2a34394..b05af7138b8 100644
--- a/tests/baselines/reference/unionTypeFromArrayLiteral.js
+++ b/tests/baselines/reference/unionTypeFromArrayLiteral.js
@@ -54,7 +54,7 @@ var D = (function () {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.foo3 = function () { };
     return E;
@@ -62,7 +62,7 @@ var E = (function (_super) {
 var F = (function (_super) {
     __extends(F, _super);
     function F() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     F.prototype.foo4 = function () { };
     return F;
diff --git a/tests/baselines/reference/unionTypesAssignability.js b/tests/baselines/reference/unionTypesAssignability.js
index 231b8b27f3b..d558c3a2108 100644
--- a/tests/baselines/reference/unionTypesAssignability.js
+++ b/tests/baselines/reference/unionTypesAssignability.js
@@ -88,7 +88,7 @@ var C = (function () {
 var D = (function (_super) {
     __extends(D, _super);
     function D() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     D.prototype.foo1 = function () { };
     return D;
@@ -96,7 +96,7 @@ var D = (function (_super) {
 var E = (function (_super) {
     __extends(E, _super);
     function E() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     E.prototype.foo2 = function () { };
     return E;
diff --git a/tests/baselines/reference/unspecializedConstraints.js b/tests/baselines/reference/unspecializedConstraints.js
index 1343bea602e..21f63a8de97 100644
--- a/tests/baselines/reference/unspecializedConstraints.js
+++ b/tests/baselines/reference/unspecializedConstraints.js
@@ -169,7 +169,7 @@ var ts;
     var Type = (function (_super) {
         __extends(Type, _super);
         function Type() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         Type.prototype.equals = function (that) {
             if (this === that)
diff --git a/tests/baselines/reference/untypedFunctionCallsWithTypeParameters1.js b/tests/baselines/reference/untypedFunctionCallsWithTypeParameters1.js
index b82a7cbc0ae..9a2a124e0c2 100644
--- a/tests/baselines/reference/untypedFunctionCallsWithTypeParameters1.js
+++ b/tests/baselines/reference/untypedFunctionCallsWithTypeParameters1.js
@@ -70,7 +70,7 @@ var r4 = c2(); // should be an error
 var C2 = (function (_super) {
     __extends(C2, _super);
     function C2() {
-        return _super.apply(this, arguments) || this;
+        return _super !== null && _super.apply(this, arguments) || this;
     }
     return C2;
 }(Function)); // error
diff --git a/tests/baselines/reference/unusedClassesinNamespace4.js b/tests/baselines/reference/unusedClassesinNamespace4.js
index 0ab1227bf3d..8325405e301 100644
--- a/tests/baselines/reference/unusedClassesinNamespace4.js
+++ b/tests/baselines/reference/unusedClassesinNamespace4.js
@@ -36,7 +36,7 @@ var Validation;
     var c3 = (function (_super) {
         __extends(c3, _super);
         function c3() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return c3;
     }(c1));
diff --git a/tests/baselines/reference/unusedIdentifiersConsolidated1.js b/tests/baselines/reference/unusedIdentifiersConsolidated1.js
index dbb261e5f2a..a10458d9454 100644
--- a/tests/baselines/reference/unusedIdentifiersConsolidated1.js
+++ b/tests/baselines/reference/unusedIdentifiersConsolidated1.js
@@ -168,7 +168,7 @@ var Greeter;
     var class2 = (function (_super) {
         __extends(class2, _super);
         function class2() {
-            return _super.apply(this, arguments) || this;
+            return _super !== null && _super.apply(this, arguments) || this;
         }
         return class2;
     }(class1));