diff --git a/tests/baselines/reference/badOverloadError.types b/tests/baselines/reference/badOverloadError.types
index b8ae583a73c..198582af2db 100644
--- a/tests/baselines/reference/badOverloadError.types
+++ b/tests/baselines/reference/badOverloadError.types
@@ -6,6 +6,6 @@ function method() {
 >dictionary : { [index: string]: string; }
 ><{ [index: string]: string; }>{} : { [index: string]: string; }
 >index : string
->{} : { [x: string]: undefined; }
+>{} : {}
 }
 
diff --git a/tests/baselines/reference/bestCommonTypeWithContextualTyping.types b/tests/baselines/reference/bestCommonTypeWithContextualTyping.types
index 628fe82012a..5baca43b752 100644
--- a/tests/baselines/reference/bestCommonTypeWithContextualTyping.types
+++ b/tests/baselines/reference/bestCommonTypeWithContextualTyping.types
@@ -36,7 +36,7 @@ var obj: { [s: string]: Contextual } = { s: e }; // { s: Ellement; [s: string]:
 >obj : { [s: string]: Contextual; }
 >s : string
 >Contextual : Contextual
->{ s: e } : { [x: string]: Ellement; s: Ellement; }
+>{ s: e } : { s: Ellement; }
 >s : Ellement
 >e : Ellement
 
diff --git a/tests/baselines/reference/compoundAdditionAssignmentLHSCanBeAssigned.types b/tests/baselines/reference/compoundAdditionAssignmentLHSCanBeAssigned.types
index 92835611c6d..e40422450b4 100644
--- a/tests/baselines/reference/compoundAdditionAssignmentLHSCanBeAssigned.types
+++ b/tests/baselines/reference/compoundAdditionAssignmentLHSCanBeAssigned.types
@@ -98,7 +98,7 @@ x2 += E.a;
 x2 += {};
 >x2 += {} : string
 >x2 : string
->{} : { [x: number]: undefined; }
+>{} : {}
 
 x2 += null;
 >x2 += null : string
diff --git a/tests/baselines/reference/constEnumPropertyAccess1.types b/tests/baselines/reference/constEnumPropertyAccess1.types
index 5ed2b932bd0..f0e00fe7717 100644
--- a/tests/baselines/reference/constEnumPropertyAccess1.types
+++ b/tests/baselines/reference/constEnumPropertyAccess1.types
@@ -35,7 +35,7 @@ var o: {
 >idx : number
 
 } = {
->{        1: true    } : { [x: number]: boolean; 1: boolean; }
+>{        1: true    } : { 1: boolean; }
 
         1: true
 >true : boolean
diff --git a/tests/baselines/reference/contextualTypeAny.errors.txt b/tests/baselines/reference/contextualTypeAny.errors.txt
new file mode 100644
index 00000000000..09970be986d
--- /dev/null
+++ b/tests/baselines/reference/contextualTypeAny.errors.txt
@@ -0,0 +1,15 @@
+tests/cases/compiler/contextualTypeAny.ts(3,5): error TS2322: Type '{ p: string; q: any; }' is not assignable to type '{ [s: string]: number; }'.
+  Property 'p' is incompatible with index signature.
+    Type 'string' is not assignable to type 'number'.
+
+
+==== tests/cases/compiler/contextualTypeAny.ts (1 errors) ====
+    var x: any;
+    
+    var obj: { [s: string]: number } = { p: "", q: x };
+        ~~~
+!!! error TS2322: Type '{ p: string; q: any; }' is not assignable to type '{ [s: string]: number; }'.
+!!! error TS2322:   Property 'p' is incompatible with index signature.
+!!! error TS2322:     Type 'string' is not assignable to type 'number'.
+    
+    var arr: number[] = ["", x];
\ No newline at end of file
diff --git a/tests/baselines/reference/contextualTypeAny.symbols b/tests/baselines/reference/contextualTypeAny.symbols
deleted file mode 100644
index 5132c948a2e..00000000000
--- a/tests/baselines/reference/contextualTypeAny.symbols
+++ /dev/null
@@ -1,15 +0,0 @@
-=== tests/cases/compiler/contextualTypeAny.ts ===
-var x: any;
->x : Symbol(x, Decl(contextualTypeAny.ts, 0, 3))
-
-var obj: { [s: string]: number } = { p: "", q: x };
->obj : Symbol(obj, Decl(contextualTypeAny.ts, 2, 3))
->s : Symbol(s, Decl(contextualTypeAny.ts, 2, 12))
->p : Symbol(p, Decl(contextualTypeAny.ts, 2, 36))
->q : Symbol(q, Decl(contextualTypeAny.ts, 2, 43))
->x : Symbol(x, Decl(contextualTypeAny.ts, 0, 3))
-
-var arr: number[] = ["", x];
->arr : Symbol(arr, Decl(contextualTypeAny.ts, 4, 3))
->x : Symbol(x, Decl(contextualTypeAny.ts, 0, 3))
-
diff --git a/tests/baselines/reference/contextualTypeAny.types b/tests/baselines/reference/contextualTypeAny.types
deleted file mode 100644
index cace92d6567..00000000000
--- a/tests/baselines/reference/contextualTypeAny.types
+++ /dev/null
@@ -1,19 +0,0 @@
-=== tests/cases/compiler/contextualTypeAny.ts ===
-var x: any;
->x : any
-
-var obj: { [s: string]: number } = { p: "", q: x };
->obj : { [s: string]: number; }
->s : string
->{ p: "", q: x } : { [x: string]: any; p: string; q: any; }
->p : string
->"" : string
->q : any
->x : any
-
-var arr: number[] = ["", x];
->arr : number[]
->["", x] : any[]
->"" : string
->x : any
-
diff --git a/tests/baselines/reference/contextualTypeArrayReturnType.types b/tests/baselines/reference/contextualTypeArrayReturnType.types
index f270b33f568..6c91fd7b8b9 100644
--- a/tests/baselines/reference/contextualTypeArrayReturnType.types
+++ b/tests/baselines/reference/contextualTypeArrayReturnType.types
@@ -26,18 +26,18 @@ interface Transform3D {
 var style: IBookStyle = {
 >style : IBookStyle
 >IBookStyle : IBookStyle
->{    initialLeftPageTransforms: (width: number) => {        return [            {'ry': null }        ];    }} : { initialLeftPageTransforms: (width: number) => { [x: string]: any; 'ry': any; }[]; }
+>{    initialLeftPageTransforms: (width: number) => {        return [            {'ry': null }        ];    }} : { initialLeftPageTransforms: (width: number) => { 'ry': any; }[]; }
 
     initialLeftPageTransforms: (width: number) => {
->initialLeftPageTransforms : (width: number) => { [x: string]: any; 'ry': any; }[]
->(width: number) => {        return [            {'ry': null }        ];    } : (width: number) => { [x: string]: any; 'ry': any; }[]
+>initialLeftPageTransforms : (width: number) => { 'ry': any; }[]
+>(width: number) => {        return [            {'ry': null }        ];    } : (width: number) => { 'ry': any; }[]
 >width : number
 
         return [
->[            {'ry': null }        ] : { [x: string]: null; 'ry': null; }[]
+>[            {'ry': null }        ] : { 'ry': null; }[]
 
             {'ry': null }
->{'ry': null } : { [x: string]: null; 'ry': null; }
+>{'ry': null } : { 'ry': null; }
 >null : null
 
         ];
diff --git a/tests/baselines/reference/contextualTypeWithUnionTypeIndexSignatures.types b/tests/baselines/reference/contextualTypeWithUnionTypeIndexSignatures.types
index 2f24ad08227..965e4d21d99 100644
--- a/tests/baselines/reference/contextualTypeWithUnionTypeIndexSignatures.types
+++ b/tests/baselines/reference/contextualTypeWithUnionTypeIndexSignatures.types
@@ -69,7 +69,7 @@ var x: IWithNoStringIndexSignature | IWithStringIndexSignature1 = { z: a => a };
 >x : IWithNoStringIndexSignature | IWithStringIndexSignature1
 >IWithNoStringIndexSignature : IWithNoStringIndexSignature
 >IWithStringIndexSignature1 : IWithStringIndexSignature1
->{ z: a => a } : { [x: string]: (a: number) => number; z: (a: number) => number; }
+>{ z: a => a } : { z: (a: number) => number; }
 >z : (a: number) => number
 >a => a : (a: number) => number
 >a : number
@@ -79,7 +79,7 @@ var x: IWithNoStringIndexSignature | IWithStringIndexSignature1 = { foo: a => a
 >x : IWithNoStringIndexSignature | IWithStringIndexSignature1
 >IWithNoStringIndexSignature : IWithNoStringIndexSignature
 >IWithStringIndexSignature1 : IWithStringIndexSignature1
->{ foo: a => a } : { [x: string]: (a: any) => any; foo: (a: any) => any; }
+>{ foo: a => a } : { foo: (a: any) => any; }
 >foo : (a: any) => any
 >a => a : (a: any) => any
 >a : any
@@ -89,7 +89,7 @@ var x: IWithNoStringIndexSignature | IWithStringIndexSignature1 = { foo: "hello"
 >x : IWithNoStringIndexSignature | IWithStringIndexSignature1
 >IWithNoStringIndexSignature : IWithNoStringIndexSignature
 >IWithStringIndexSignature1 : IWithStringIndexSignature1
->{ foo: "hello" } : { [x: string]: string; foo: string; }
+>{ foo: "hello" } : { foo: string; }
 >foo : string
 >"hello" : string
 
@@ -97,7 +97,7 @@ var x2: IWithStringIndexSignature1 | IWithStringIndexSignature2 = { z: a => a.to
 >x2 : IWithStringIndexSignature1 | IWithStringIndexSignature2
 >IWithStringIndexSignature1 : IWithStringIndexSignature1
 >IWithStringIndexSignature2 : IWithStringIndexSignature2
->{ z: a => a.toString() } : { [x: string]: (a: number) => string; z: (a: number) => string; }
+>{ z: a => a.toString() } : { z: (a: number) => string; }
 >z : (a: number) => string
 >a => a.toString() : (a: number) => string
 >a : number
@@ -110,7 +110,7 @@ var x2: IWithStringIndexSignature1 | IWithStringIndexSignature2 = { z: a => a };
 >x2 : IWithStringIndexSignature1 | IWithStringIndexSignature2
 >IWithStringIndexSignature1 : IWithStringIndexSignature1
 >IWithStringIndexSignature2 : IWithStringIndexSignature2
->{ z: a => a } : { [x: string]: (a: number) => number; z: (a: number) => number; }
+>{ z: a => a } : { z: (a: number) => number; }
 >z : (a: number) => number
 >a => a : (a: number) => number
 >a : number
@@ -124,7 +124,7 @@ var x3: IWithNoNumberIndexSignature | IWithNumberIndexSignature1 = { 1: a => a }
 >x3 : IWithNoNumberIndexSignature | IWithNumberIndexSignature1
 >IWithNoNumberIndexSignature : IWithNoNumberIndexSignature
 >IWithNumberIndexSignature1 : IWithNumberIndexSignature1
->{ 1: a => a } : { [x: number]: (a: number) => number; 1: (a: number) => number; }
+>{ 1: a => a } : { 1: (a: number) => number; }
 >a => a : (a: number) => number
 >a : number
 >a : number
@@ -133,7 +133,7 @@ var x3: IWithNoNumberIndexSignature | IWithNumberIndexSignature1 = { 0: a => a }
 >x3 : IWithNoNumberIndexSignature | IWithNumberIndexSignature1
 >IWithNoNumberIndexSignature : IWithNoNumberIndexSignature
 >IWithNumberIndexSignature1 : IWithNumberIndexSignature1
->{ 0: a => a } : { [x: number]: (a: any) => any; 0: (a: any) => any; }
+>{ 0: a => a } : { 0: (a: any) => any; }
 >a => a : (a: any) => any
 >a : any
 >a : any
@@ -142,14 +142,14 @@ var x3: IWithNoNumberIndexSignature | IWithNumberIndexSignature1 = { 0: "hello"
 >x3 : IWithNoNumberIndexSignature | IWithNumberIndexSignature1
 >IWithNoNumberIndexSignature : IWithNoNumberIndexSignature
 >IWithNumberIndexSignature1 : IWithNumberIndexSignature1
->{ 0: "hello" } : { [x: number]: string; 0: string; }
+>{ 0: "hello" } : { 0: string; }
 >"hello" : string
 
 var x4: IWithNumberIndexSignature1 | IWithNumberIndexSignature2 = { 1: a => a.toString() }; // a should be number
 >x4 : IWithNumberIndexSignature1 | IWithNumberIndexSignature2
 >IWithNumberIndexSignature1 : IWithNumberIndexSignature1
 >IWithNumberIndexSignature2 : IWithNumberIndexSignature2
->{ 1: a => a.toString() } : { [x: number]: (a: number) => string; 1: (a: number) => string; }
+>{ 1: a => a.toString() } : { 1: (a: number) => string; }
 >a => a.toString() : (a: number) => string
 >a : number
 >a.toString() : string
@@ -161,7 +161,7 @@ var x4: IWithNumberIndexSignature1 | IWithNumberIndexSignature2 = { 1: a => a };
 >x4 : IWithNumberIndexSignature1 | IWithNumberIndexSignature2
 >IWithNumberIndexSignature1 : IWithNumberIndexSignature1
 >IWithNumberIndexSignature2 : IWithNumberIndexSignature2
->{ 1: a => a } : { [x: number]: (a: number) => number; 1: (a: number) => number; }
+>{ 1: a => a } : { 1: (a: number) => number; }
 >a => a : (a: number) => number
 >a : number
 >a : number
diff --git a/tests/baselines/reference/contextualTypingOfObjectLiterals.types b/tests/baselines/reference/contextualTypingOfObjectLiterals.types
index 5b3068e8029..a99fb2f39af 100644
--- a/tests/baselines/reference/contextualTypingOfObjectLiterals.types
+++ b/tests/baselines/reference/contextualTypingOfObjectLiterals.types
@@ -10,9 +10,9 @@ var obj2 = {x: ""};
 >"" : string
 
 obj1 = {}; // Ok
->obj1 = {} : { [x: string]: undefined; }
+>obj1 = {} : {}
 >obj1 : { [x: string]: string; }
->{} : { [x: string]: undefined; }
+>{} : {}
 
 obj1 = obj2; // Error - indexer doesn't match
 >obj1 = obj2 : { x: string; }
@@ -27,7 +27,7 @@ function f(x: { [s: string]: string }) { }
 f({}); // Ok
 >f({}) : void
 >f : (x: { [s: string]: string; }) => void
->{} : { [x: string]: undefined; }
+>{} : {}
 
 f(obj1); // Ok
 >f(obj1) : void
diff --git a/tests/baselines/reference/declarationsAndAssignments.errors.txt b/tests/baselines/reference/declarationsAndAssignments.errors.txt
index 7c4671022ea..517eaafe4ab 100644
--- a/tests/baselines/reference/declarationsAndAssignments.errors.txt
+++ b/tests/baselines/reference/declarationsAndAssignments.errors.txt
@@ -11,8 +11,8 @@ tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(62,13):
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(62,16): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(63,13): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(63,16): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
-tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(67,9): error TS2461: Type '{ [x: number]: undefined; }' is not an array type.
-tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(68,9): error TS2461: Type '{ [x: number]: number; 0: number; 1: number; }' is not an array type.
+tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(67,9): error TS2461: Type '{}' is not an array type.
+tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(68,9): error TS2461: Type '{ 0: number; 1: number; }' is not an array type.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(73,11): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(73,14): error TS2525: Initializer provides no value for this binding element and the binding element has no default value.
 tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(74,11): error TS2459: Type 'undefined[]' has no property 'a' and no string index signature.
@@ -122,10 +122,10 @@ tests/cases/conformance/es6/destructuring/declarationsAndAssignments.ts(138,9):
     function f9() {
         var [a, b] = {};                // Error, not array type
             ~~~~~~
-!!! error TS2461: Type '{ [x: number]: undefined; }' is not an array type.
+!!! error TS2461: Type '{}' is not an array type.
         var [c, d] = { 0: 10, 1: 20 };  // Error, not array type
             ~~~~~~
-!!! error TS2461: Type '{ [x: number]: number; 0: number; 1: number; }' is not an array type.
+!!! error TS2461: Type '{ 0: number; 1: number; }' is not an array type.
         var [e, f] = [10, 20];
     }
     
diff --git a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment1ES5.types b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment1ES5.types
index 476b5bee0cc..cb6052d93fd 100644
--- a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment1ES5.types
+++ b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment1ES5.types
@@ -69,7 +69,7 @@ function foo(): F {
 >F : F
 
     return {
->{        1: true    } : { [x: number]: boolean; 1: boolean; }
+>{        1: true    } : { 1: boolean; }
 
         1: true
 >true : boolean
@@ -82,7 +82,7 @@ function bar(): F {
 >F : F
 
     return {
->{        2: true    } : { [x: number]: boolean; 2: boolean; }
+>{        2: true    } : { 2: boolean; }
 
         2: true
 >true : boolean
@@ -114,7 +114,7 @@ function foo1(): F1 {
 >F1 : F1
 
     return {
->{        "prop1": 2    } : { [x: string]: number; "prop1": number; }
+>{        "prop1": 2    } : { "prop1": number; }
 
         "prop1": 2
 >2 : number
diff --git a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment1ES6.types b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment1ES6.types
index 7a7f631eddf..2d77c20f65b 100644
--- a/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment1ES6.types
+++ b/tests/baselines/reference/destructuringObjectBindingPatternAndAssignment1ES6.types
@@ -69,7 +69,7 @@ function foo(): F {
 >F : F
 
     return {
->{        1: true    } : { [x: number]: boolean; 1: boolean; }
+>{        1: true    } : { 1: boolean; }
 
         1: true
 >true : boolean
@@ -82,7 +82,7 @@ function bar(): F {
 >F : F
 
     return {
->{        2: true    } : { [x: number]: boolean; 2: boolean; }
+>{        2: true    } : { 2: boolean; }
 
         2: true
 >true : boolean
@@ -114,7 +114,7 @@ function foo1(): F1 {
 >F1 : F1
 
     return {
->{        "prop1": 2    } : { [x: string]: number; "prop1": number; }
+>{        "prop1": 2    } : { "prop1": number; }
 
         "prop1": 2
 >2 : number
diff --git a/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.types b/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.types
index e1bfd195698..9825a75a220 100644
--- a/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.types
+++ b/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.types
@@ -26,7 +26,7 @@ var moduleMap: { [key: string]: IHasVisualizationModel } = {
 >moduleMap : { [key: string]: IHasVisualizationModel; }
 >key : string
 >IHasVisualizationModel : IHasVisualizationModel
->{    "moduleA": moduleA,    "moduleB": moduleB} : { [x: string]: typeof moduleA; "moduleA": typeof moduleA; "moduleB": typeof moduleB; }
+>{    "moduleA": moduleA,    "moduleB": moduleB} : { "moduleA": typeof moduleA; "moduleB": typeof moduleB; }
 
     "moduleA": moduleA,
 >moduleA : typeof moduleA
diff --git a/tests/baselines/reference/genericBaseClassLiteralProperty2.types b/tests/baselines/reference/genericBaseClassLiteralProperty2.types
index d7d512165f0..3e320824925 100644
--- a/tests/baselines/reference/genericBaseClassLiteralProperty2.types
+++ b/tests/baselines/reference/genericBaseClassLiteralProperty2.types
@@ -14,11 +14,11 @@ class BaseCollection2<TItem extends CollectionItem2> {
 
     constructor() {
         this._itemsByKey = {};
->this._itemsByKey = {} : { [x: string]: undefined; }
+>this._itemsByKey = {} : {}
 >this._itemsByKey : { [key: string]: TItem; }
 >this : this
 >_itemsByKey : { [key: string]: TItem; }
->{} : { [x: string]: undefined; }
+>{} : {}
     }
 }
 
diff --git a/tests/baselines/reference/genericCallWithTupleType.errors.txt b/tests/baselines/reference/genericCallWithTupleType.errors.txt
index d03f8d5e68a..bcf580320e5 100644
--- a/tests/baselines/reference/genericCallWithTupleType.errors.txt
+++ b/tests/baselines/reference/genericCallWithTupleType.errors.txt
@@ -9,9 +9,9 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTup
 tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTupleType.ts(22,1): error TS2322: Type '[number, string]' is not assignable to type '[string, number]'.
   Types of property '0' are incompatible.
     Type 'number' is not assignable to type 'string'.
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTupleType.ts(23,1): error TS2322: Type '[{ [x: number]: undefined; }, {}]' is not assignable to type '[string, number]'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTupleType.ts(23,1): error TS2322: Type '[{}, {}]' is not assignable to type '[string, number]'.
   Types of property '0' are incompatible.
-    Type '{ [x: number]: undefined; }' is not assignable to type 'string'.
+    Type '{}' is not assignable to type 'string'.
 tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTupleType.ts(24,1): error TS2322: Type '[{}]' is not assignable to type '[{}, {}]'.
   Property '1' is missing in type '[{}]'.
 
@@ -55,9 +55,9 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithTup
 !!! error TS2322:     Type 'number' is not assignable to type 'string'.
     i1.tuple1 = [{}, {}];
     ~~~~~~~~~
-!!! error TS2322: Type '[{ [x: number]: undefined; }, {}]' is not assignable to type '[string, number]'.
+!!! error TS2322: Type '[{}, {}]' is not assignable to type '[string, number]'.
 !!! error TS2322:   Types of property '0' are incompatible.
-!!! error TS2322:     Type '{ [x: number]: undefined; }' is not assignable to type 'string'.
+!!! error TS2322:     Type '{}' is not assignable to type 'string'.
     i2.tuple1 = [{}];
     ~~~~~~~~~
 !!! error TS2322: Type '[{}]' is not assignable to type '[{}, {}]'.
diff --git a/tests/baselines/reference/genericWithIndexerOfTypeParameterType1.types b/tests/baselines/reference/genericWithIndexerOfTypeParameterType1.types
index 337993dc2a6..a316773e5c8 100644
--- a/tests/baselines/reference/genericWithIndexerOfTypeParameterType1.types
+++ b/tests/baselines/reference/genericWithIndexerOfTypeParameterType1.types
@@ -8,7 +8,7 @@ class LazyArray<T> {
 ><{ [objectId: string]: T; }>{} : { [objectId: string]: T; }
 >objectId : string
 >T : T
->{} : { [x: string]: undefined; }
+>{} : {}
 
     array() {
 >array : () => { [objectId: string]: T; }
diff --git a/tests/baselines/reference/indexSignaturesInferentialTyping.types b/tests/baselines/reference/indexSignaturesInferentialTyping.types
index 328dbc18e4f..8545a7d4ca9 100644
--- a/tests/baselines/reference/indexSignaturesInferentialTyping.types
+++ b/tests/baselines/reference/indexSignaturesInferentialTyping.types
@@ -21,15 +21,15 @@ var x1 = foo({ 0: 0, 1: 1 });       // type should be number
 >x1 : number
 >foo({ 0: 0, 1: 1 }) : number
 >foo : <T>(items: { [index: number]: T; }) => T
->{ 0: 0, 1: 1 } : { [x: number]: number; 0: number; 1: number; }
+>{ 0: 0, 1: 1 } : { 0: number; 1: number; }
 >0 : number
 >1 : number
 
 var x2 = foo({ zero: 0, one: 1 });
->x2 : any
->foo({ zero: 0, one: 1 }) : any
+>x2 : {}
+>foo({ zero: 0, one: 1 }) : {}
 >foo : <T>(items: { [index: number]: T; }) => T
->{ zero: 0, one: 1 } : { [x: number]: undefined; zero: number; one: number; }
+>{ zero: 0, one: 1 } : { zero: number; one: number; }
 >zero : number
 >0 : number
 >one : number
@@ -39,7 +39,7 @@ var x3 = bar({ 0: 0, 1: 1 });
 >x3 : number
 >bar({ 0: 0, 1: 1 }) : number
 >bar : <T>(items: { [index: string]: T; }) => T
->{ 0: 0, 1: 1 } : { [x: string]: number; 0: number; 1: number; }
+>{ 0: 0, 1: 1 } : { 0: number; 1: number; }
 >0 : number
 >1 : number
 
@@ -47,7 +47,7 @@ var x4 = bar({ zero: 0, one: 1 });  // type should be number
 >x4 : number
 >bar({ zero: 0, one: 1 }) : number
 >bar : <T>(items: { [index: string]: T; }) => T
->{ zero: 0, one: 1 } : { [x: string]: number; zero: number; one: number; }
+>{ zero: 0, one: 1 } : { zero: number; one: number; }
 >zero : number
 >0 : number
 >one : number
diff --git a/tests/baselines/reference/indexer.types b/tests/baselines/reference/indexer.types
index a0142bb9383..f24c90f6ea1 100644
--- a/tests/baselines/reference/indexer.types
+++ b/tests/baselines/reference/indexer.types
@@ -17,7 +17,7 @@ interface JQuery {
 var jq:JQuery={ 0: { id : "a" }, 1: { id : "b" } };
 >jq : JQuery
 >JQuery : JQuery
->{ 0: { id : "a" }, 1: { id : "b" } } : { [x: number]: { id: string; }; 0: { id: string; }; 1: { id: string; }; }
+>{ 0: { id : "a" }, 1: { id : "b" } } : { 0: { id: string; }; 1: { id: string; }; }
 >{ id : "a" } : { id: string; }
 >id : string
 >"a" : string
diff --git a/tests/baselines/reference/indexer2.types b/tests/baselines/reference/indexer2.types
index 7f1ccd41cb5..ff82707edd3 100644
--- a/tests/baselines/reference/indexer2.types
+++ b/tests/baselines/reference/indexer2.types
@@ -17,5 +17,5 @@ var directChildrenMap = <IDirectChildrenMap>{};
 >directChildrenMap : IDirectChildrenMap
 ><IDirectChildrenMap>{} : IDirectChildrenMap
 >IDirectChildrenMap : IDirectChildrenMap
->{} : { [x: number]: undefined; }
+>{} : {}
 
diff --git a/tests/baselines/reference/indexer3.types b/tests/baselines/reference/indexer3.types
index 8f0582f782a..28bcd9cab0c 100644
--- a/tests/baselines/reference/indexer3.types
+++ b/tests/baselines/reference/indexer3.types
@@ -3,7 +3,7 @@ var dateMap: { [x: string]: Date; } = {}
 >dateMap : { [x: string]: Date; }
 >x : string
 >Date : Date
->{} : { [x: string]: undefined; }
+>{} : {}
 
 var r: Date = dateMap["hello"] // result type includes indexer using BCT
 >r : Date
diff --git a/tests/baselines/reference/indexerA.types b/tests/baselines/reference/indexerA.types
index c6ff81b3a26..ee6351eae33 100644
--- a/tests/baselines/reference/indexerA.types
+++ b/tests/baselines/reference/indexerA.types
@@ -17,7 +17,7 @@ class JQuery {
 var jq:JQuery={ 0: { id : "a" }, 1: { id : "b" } };
 >jq : JQuery
 >JQuery : JQuery
->{ 0: { id : "a" }, 1: { id : "b" } } : { [x: number]: { id: string; }; 0: { id: string; }; 1: { id: string; }; }
+>{ 0: { id : "a" }, 1: { id : "b" } } : { 0: { id: string; }; 1: { id: string; }; }
 >{ id : "a" } : { id: string; }
 >id : string
 >"a" : string
diff --git a/tests/baselines/reference/inferentialTypingObjectLiteralMethod2.types b/tests/baselines/reference/inferentialTypingObjectLiteralMethod2.types
index be937410cef..f70305739b8 100644
--- a/tests/baselines/reference/inferentialTypingObjectLiteralMethod2.types
+++ b/tests/baselines/reference/inferentialTypingObjectLiteralMethod2.types
@@ -30,13 +30,13 @@ foo("", { method(p1) { return p1.length } }, { method(p2) { return undefined } }
 >foo("", { method(p1) { return p1.length } }, { method(p2) { return undefined } }) : string
 >foo : <T, U>(x: T, y: Int<T, U>, z: Int<U, T>) => T
 >"" : string
->{ method(p1) { return p1.length } } : { [x: string]: (p1: string) => number; method(p1: string): number; }
+>{ method(p1) { return p1.length } } : { method(p1: string): number; }
 >method : (p1: string) => number
 >p1 : string
 >p1.length : number
 >p1 : string
 >length : number
->{ method(p2) { return undefined } } : { [x: string]: (p2: number) => any; method(p2: number): any; }
+>{ method(p2) { return undefined } } : { method(p2: number): any; }
 >method : (p2: number) => any
 >p2 : number
 >undefined : undefined
diff --git a/tests/baselines/reference/inferentialTypingUsingApparentType3.types b/tests/baselines/reference/inferentialTypingUsingApparentType3.types
index 9e0a4ceaea6..e375fe981e8 100644
--- a/tests/baselines/reference/inferentialTypingUsingApparentType3.types
+++ b/tests/baselines/reference/inferentialTypingUsingApparentType3.types
@@ -49,10 +49,10 @@ class ObjectField<A, T extends { [name: string]: Field<any> }> {
 }
 
 var person = new ObjectField({
->person : ObjectField<{}, { [x: string]: NumberField | CharField; id: NumberField; name: CharField; }>
->new ObjectField({    id: new NumberField(),    name: new CharField()}) : ObjectField<{}, { [x: string]: NumberField | CharField; id: NumberField; name: CharField; }>
+>person : ObjectField<{}, { id: NumberField; name: CharField; }>
+>new ObjectField({    id: new NumberField(),    name: new CharField()}) : ObjectField<{}, { id: NumberField; name: CharField; }>
 >ObjectField : typeof ObjectField
->{    id: new NumberField(),    name: new CharField()} : { [x: string]: NumberField | CharField; id: NumberField; name: CharField; }
+>{    id: new NumberField(),    name: new CharField()} : { id: NumberField; name: CharField; }
 
     id: new NumberField(),
 >id : NumberField
@@ -68,8 +68,8 @@ var person = new ObjectField({
 
 person.fields.id;
 >person.fields.id : NumberField
->person.fields : { [x: string]: NumberField | CharField; id: NumberField; name: CharField; }
->person : ObjectField<{}, { [x: string]: NumberField | CharField; id: NumberField; name: CharField; }>
->fields : { [x: string]: NumberField | CharField; id: NumberField; name: CharField; }
+>person.fields : { id: NumberField; name: CharField; }
+>person : ObjectField<{}, { id: NumberField; name: CharField; }>
+>fields : { id: NumberField; name: CharField; }
 >id : NumberField
 
diff --git a/tests/baselines/reference/interfaceContextualType.types b/tests/baselines/reference/interfaceContextualType.types
index e827f9a9d9b..0e835a2f1f9 100644
--- a/tests/baselines/reference/interfaceContextualType.types
+++ b/tests/baselines/reference/interfaceContextualType.types
@@ -27,11 +27,11 @@ class Bug {
 >ok : () => void
 
         this.values = {};
->this.values = {} : { [x: string]: undefined; }
+>this.values = {} : {}
 >this.values : IMap
 >this : this
 >values : IMap
->{} : { [x: string]: undefined; }
+>{} : {}
 
         this.values['comments'] = { italic: true };
 >this.values['comments'] = { italic: true } : { italic: boolean; }
@@ -48,11 +48,11 @@ class Bug {
 >shouldBeOK : () => void
 
         this.values = {
->this.values = {            comments: { italic: true }        } : { [x: string]: { italic: boolean; }; comments: { italic: boolean; }; }
+>this.values = {            comments: { italic: true }        } : { comments: { italic: boolean; }; }
 >this.values : IMap
 >this : this
 >values : IMap
->{            comments: { italic: true }        } : { [x: string]: { italic: boolean; }; comments: { italic: boolean; }; }
+>{            comments: { italic: true }        } : { comments: { italic: boolean; }; }
 
             comments: { italic: true }
 >comments : { italic: boolean; }
diff --git a/tests/baselines/reference/noErrorsInCallback.errors.txt b/tests/baselines/reference/noErrorsInCallback.errors.txt
index 90fdbbd77a5..f0bfe00199e 100644
--- a/tests/baselines/reference/noErrorsInCallback.errors.txt
+++ b/tests/baselines/reference/noErrorsInCallback.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/compiler/noErrorsInCallback.ts(4,19): error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'string'.
-tests/cases/compiler/noErrorsInCallback.ts(6,23): error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'string'.
+tests/cases/compiler/noErrorsInCallback.ts(4,19): error TS2345: Argument of type '{}' is not assignable to parameter of type 'string'.
+tests/cases/compiler/noErrorsInCallback.ts(6,23): error TS2345: Argument of type '{}' is not assignable to parameter of type 'string'.
 
 
 ==== tests/cases/compiler/noErrorsInCallback.ts (2 errors) ====
@@ -8,10 +8,10 @@ tests/cases/compiler/noErrorsInCallback.ts(6,23): error TS2345: Argument of type
     }
     var one = new Bar({}); // Error
                       ~~
-!!! error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'string'.
+!!! error TS2345: Argument of type '{}' is not assignable to parameter of type 'string'.
     [].forEach(() => {
         var two = new Bar({}); // No error?
                           ~~
-!!! error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'string'.
+!!! error TS2345: Argument of type '{}' is not assignable to parameter of type 'string'.
     });
      
\ No newline at end of file
diff --git a/tests/baselines/reference/noImplicitAnyIndexingSuppressed.types b/tests/baselines/reference/noImplicitAnyIndexingSuppressed.types
index b7b21bf8f92..d82b37e0f9e 100644
--- a/tests/baselines/reference/noImplicitAnyIndexingSuppressed.types
+++ b/tests/baselines/reference/noImplicitAnyIndexingSuppressed.types
@@ -87,7 +87,7 @@ interface MyMap<T> {
 var m: MyMap<number> = {
 >m : MyMap<number>
 >MyMap : MyMap<T>
->{    "0": 0,    "1": 1,    "2": 2,    "Okay that's enough for today.": NaN} : { [x: string]: number; "0": number; "1": number; "2": number; "Okay that's enough for today.": number; }
+>{    "0": 0,    "1": 1,    "2": 2,    "Okay that's enough for today.": NaN} : { "0": number; "1": number; "2": number; "Okay that's enough for today.": number; }
 
     "0": 0,
 >0 : number
diff --git a/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations.errors.txt b/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations.errors.txt
index 35673eb3072..bb01b2fe125 100644
--- a/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations.errors.txt
+++ b/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations.errors.txt
@@ -5,10 +5,9 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(36,16): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(50,5): error TS2412: Property '2.0' of type 'number' is not assignable to numeric index type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(68,5): error TS2412: Property '2.0' of type 'number' is not assignable to numeric index type 'string'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(78,5): error TS2322: Type '{ [x: number]: string | number; 1.0: string; 2.0: number; a: string; b: number; c: () => void; "d": string; "e": number; "3.0": string; "4.0": number; f: any; X: string; foo(): string; }' is not assignable to type '{ [x: number]: string; }'.
-  Index signatures are incompatible.
-    Type 'string | number' is not assignable to type 'string'.
-      Type 'number' is not assignable to type 'string'.
+tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(78,5): error TS2322: Type '{ 1.0: string; 2.0: number; a: string; b: number; c: () => void; "d": string; "e": number; "3.0": string; "4.0": number; f: any; X: string; foo(): string; }' is not assignable to type '{ [x: number]: string; }'.
+  Property '2.0' is incompatible with index signature.
+    Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(88,9): error TS2304: Cannot find name 'Myn'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(90,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(93,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
@@ -108,10 +107,9 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
     // error
     var b: { [x: number]: string; } = {
         ~
-!!! error TS2322: Type '{ [x: number]: string | number; 1.0: string; 2.0: number; a: string; b: number; c: () => void; "d": string; "e": number; "3.0": string; "4.0": number; f: any; X: string; foo(): string; }' is not assignable to type '{ [x: number]: string; }'.
-!!! error TS2322:   Index signatures are incompatible.
-!!! error TS2322:     Type 'string | number' is not assignable to type 'string'.
-!!! error TS2322:       Type 'number' is not assignable to type 'string'.
+!!! error TS2322: Type '{ 1.0: string; 2.0: number; a: string; b: number; c: () => void; "d": string; "e": number; "3.0": string; "4.0": number; f: any; X: string; foo(): string; }' is not assignable to type '{ [x: number]: string; }'.
+!!! error TS2322:   Property '2.0' is incompatible with index signature.
+!!! error TS2322:     Type 'number' is not assignable to type 'string'.
         a: '',
         b: 1, 
         c: () => { }, 
diff --git a/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.errors.txt b/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.errors.txt
index ff18160e9a5..332b356c732 100644
--- a/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.errors.txt
+++ b/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.errors.txt
@@ -1,10 +1,9 @@
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(16,5): error TS2412: Property '3.0' of type 'number' is not assignable to numeric index type 'A'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(25,5): error TS2412: Property '3.0' of type 'number' is not assignable to numeric index type 'A'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(34,5): error TS2412: Property '3.0' of type 'number' is not assignable to numeric index type 'A'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(39,5): error TS2322: Type '{ [x: number]: A | number; 1.0: A; 2.0: B; 3.0: number; "2.5": B; "4.0": string; }' is not assignable to type '{ [x: number]: A; }'.
-  Index signatures are incompatible.
-    Type 'A | number' is not assignable to type 'A'.
-      Type 'number' is not assignable to type 'A'.
+tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(39,5): error TS2322: Type '{ 1.0: A; 2.0: B; 3.0: number; "2.5": B; "4.0": string; }' is not assignable to type '{ [x: number]: A; }'.
+  Property '3.0' is incompatible with index signature.
+    Type 'number' is not assignable to type 'A'.
 
 
 ==== tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts (4 errors) ====
@@ -54,10 +53,9 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
     // error
     var b: { [x: number]: A } = {
         ~
-!!! error TS2322: Type '{ [x: number]: A | number; 1.0: A; 2.0: B; 3.0: number; "2.5": B; "4.0": string; }' is not assignable to type '{ [x: number]: A; }'.
-!!! error TS2322:   Index signatures are incompatible.
-!!! error TS2322:     Type 'A | number' is not assignable to type 'A'.
-!!! error TS2322:       Type 'number' is not assignable to type 'A'.
+!!! error TS2322: Type '{ 1.0: A; 2.0: B; 3.0: number; "2.5": B; "4.0": string; }' is not assignable to type '{ [x: number]: A; }'.
+!!! error TS2322:   Property '3.0' is incompatible with index signature.
+!!! error TS2322:     Type 'number' is not assignable to type 'A'.
         1.0: new A(), 
         2.0: new B(), 
         "2.5": new B(),
diff --git a/tests/baselines/reference/numericIndexerConstraint4.types b/tests/baselines/reference/numericIndexerConstraint4.types
index 97e72b5088d..c8af4d54a9a 100644
--- a/tests/baselines/reference/numericIndexerConstraint4.types
+++ b/tests/baselines/reference/numericIndexerConstraint4.types
@@ -22,7 +22,7 @@ var x: {
 >A : A
 
 } = { data: new B() }
->{ data: new B() } : { [x: number]: undefined; data: B; }
+>{ data: new B() } : { data: B; }
 >data : B
 >new B() : B
 >B : typeof B
diff --git a/tests/baselines/reference/numericIndexingResults.types b/tests/baselines/reference/numericIndexingResults.types
index 560bbdc74a8..9a060b388e3 100644
--- a/tests/baselines/reference/numericIndexingResults.types
+++ b/tests/baselines/reference/numericIndexingResults.types
@@ -151,7 +151,7 @@ var r6 = a[3];
 var b: { [x: number]: string } = { 1: '', "2": '' }
 >b : { [x: number]: string; }
 >x : number
->{ 1: '', "2": '' } : { [x: number]: string; 1: string; "2": string; }
+>{ 1: '', "2": '' } : { 1: string; "2": string; }
 >'' : string
 >'' : string
 
@@ -194,7 +194,7 @@ var r6 = b[3];
 var b2: { [x: number]: string; 1: string; "2": string; } = { 1: '', "2": '' }
 >b2 : { [x: number]: string; 1: string; "2": string; }
 >x : number
->{ 1: '', "2": '' } : { [x: number]: string; 1: string; "2": string; }
+>{ 1: '', "2": '' } : { 1: string; "2": string; }
 >'' : string
 >'' : string
 
diff --git a/tests/baselines/reference/objectIndexer.types b/tests/baselines/reference/objectIndexer.types
index 3dcd7bcb77e..b11c475a386 100644
--- a/tests/baselines/reference/objectIndexer.types
+++ b/tests/baselines/reference/objectIndexer.types
@@ -23,11 +23,11 @@ class Emitter {
 
     constructor () {
         this.listeners = {};
->this.listeners = {} : { [x: string]: undefined; }
+>this.listeners = {} : {}
 >this.listeners : IMap
 >this : this
 >listeners : IMap
->{} : { [x: string]: undefined; }
+>{} : {}
     }
 }
 
diff --git a/tests/baselines/reference/objectLiteralIndexerErrors.errors.txt b/tests/baselines/reference/objectLiteralIndexerErrors.errors.txt
index f825c416311..9d5ff7ea0a2 100644
--- a/tests/baselines/reference/objectLiteralIndexerErrors.errors.txt
+++ b/tests/baselines/reference/objectLiteralIndexerErrors.errors.txt
@@ -1,10 +1,13 @@
-tests/cases/compiler/objectLiteralIndexerErrors.ts(13,5): error TS2322: Type '{ [x: string]: A; [x: number]: A; 0: A; x: B; }' is not assignable to type '{ [s: string]: A; [n: number]: B; }'.
-  Index signatures are incompatible.
+tests/cases/compiler/objectLiteralIndexerErrors.ts(13,5): error TS2322: Type '{ 0: A; x: B; }' is not assignable to type '{ [s: string]: A; [n: number]: B; }'.
+  Property '0' is incompatible with index signature.
     Type 'A' is not assignable to type 'B'.
       Property 'y' is missing in type 'A'.
+tests/cases/compiler/objectLiteralIndexerErrors.ts(14,1): error TS2322: Type '{ 0: A; x: any; }' is not assignable to type '{ [s: string]: A; [n: number]: B; }'.
+  Property '0' is incompatible with index signature.
+    Type 'A' is not assignable to type 'B'.
 
 
-==== tests/cases/compiler/objectLiteralIndexerErrors.ts (1 errors) ====
+==== tests/cases/compiler/objectLiteralIndexerErrors.ts (2 errors) ====
     interface A {
         x: number;
     }
@@ -19,8 +22,12 @@ tests/cases/compiler/objectLiteralIndexerErrors.ts(13,5): error TS2322: Type '{
     
     var o1: { [s: string]: A;[n: number]: B; } = { x: b, 0: a }; // both indexers are A
         ~~
-!!! error TS2322: Type '{ [x: string]: A; [x: number]: A; 0: A; x: B; }' is not assignable to type '{ [s: string]: A; [n: number]: B; }'.
-!!! error TS2322:   Index signatures are incompatible.
+!!! error TS2322: Type '{ 0: A; x: B; }' is not assignable to type '{ [s: string]: A; [n: number]: B; }'.
+!!! error TS2322:   Property '0' is incompatible with index signature.
 !!! error TS2322:     Type 'A' is not assignable to type 'B'.
 !!! error TS2322:       Property 'y' is missing in type 'A'.
-    o1 = { x: c, 0: a }; // string indexer is any, number indexer is A
\ No newline at end of file
+    o1 = { x: c, 0: a }; // string indexer is any, number indexer is A
+    ~~
+!!! error TS2322: Type '{ 0: A; x: any; }' is not assignable to type '{ [s: string]: A; [n: number]: B; }'.
+!!! error TS2322:   Property '0' is incompatible with index signature.
+!!! error TS2322:     Type 'A' is not assignable to type 'B'.
\ No newline at end of file
diff --git a/tests/baselines/reference/objectLiteralIndexerNoImplicitAny.types b/tests/baselines/reference/objectLiteralIndexerNoImplicitAny.types
index a49f76d02e9..b0ddd9f60d0 100644
--- a/tests/baselines/reference/objectLiteralIndexerNoImplicitAny.types
+++ b/tests/baselines/reference/objectLiteralIndexerNoImplicitAny.types
@@ -9,7 +9,7 @@ interface I {
 var x: I = {
 >x : I
 >I : I
->{    p: null} : { [x: string]: null; p: null; }
+>{    p: null} : { p: null; }
 
     p: null
 >p : null
diff --git a/tests/baselines/reference/objectLiteralIndexers.types b/tests/baselines/reference/objectLiteralIndexers.types
index d5add00ebaf..9e3aa4bac49 100644
--- a/tests/baselines/reference/objectLiteralIndexers.types
+++ b/tests/baselines/reference/objectLiteralIndexers.types
@@ -31,23 +31,23 @@ var o1: { [s: string]: A;[n: number]: B; } = { x: a, 0: b }; // string indexer i
 >A : A
 >n : number
 >B : B
->{ x: a, 0: b } : { [x: string]: A; [x: number]: B; 0: B; x: A; }
+>{ x: a, 0: b } : { 0: B; x: A; }
 >x : A
 >a : A
 >b : B
 
 o1 = { x: b, 0: c }; // both indexers are any
->o1 = { x: b, 0: c } : { [x: string]: any; [x: number]: any; 0: any; x: B; }
+>o1 = { x: b, 0: c } : { 0: any; x: B; }
 >o1 : { [s: string]: A; [n: number]: B; }
->{ x: b, 0: c } : { [x: string]: any; [x: number]: any; 0: any; x: B; }
+>{ x: b, 0: c } : { 0: any; x: B; }
 >x : B
 >b : B
 >c : any
 
 o1 = { x: c, 0: b }; // string indexer is any, number indexer is B
->o1 = { x: c, 0: b } : { [x: string]: any; [x: number]: B; 0: B; x: any; }
+>o1 = { x: c, 0: b } : { 0: B; x: any; }
 >o1 : { [s: string]: A; [n: number]: B; }
->{ x: c, 0: b } : { [x: string]: any; [x: number]: B; 0: B; x: any; }
+>{ x: c, 0: b } : { 0: B; x: any; }
 >x : any
 >c : any
 >b : B
diff --git a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.types b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.types
index 2284d06ffbd..c5de5c7b9b4 100644
--- a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.types
+++ b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.types
@@ -50,7 +50,7 @@ var a: {
 var b: { [x: number]: string; } = { foo: '' };
 >b : { [x: number]: string; }
 >x : number
->{ foo: '' } : { [x: number]: undefined; foo: string; }
+>{ foo: '' } : { foo: string; }
 >foo : string
 >'' : string
 
diff --git a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.types b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.types
index 1a580297b1b..17fc6a07a00 100644
--- a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.types
+++ b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.types
@@ -64,7 +64,7 @@ var b: { [x: number]: Derived; } = { foo: <Derived>null };
 >b : { [x: number]: Derived; }
 >x : number
 >Derived : Derived
->{ foo: <Derived>null } : { [x: number]: undefined; foo: Derived; }
+>{ foo: <Derived>null } : { foo: Derived; }
 >foo : Derived
 ><Derived>null : Derived
 >Derived : Derived
diff --git a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.types b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.types
index ae384bbb4db..99e6b8c8632 100644
--- a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.types
+++ b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.types
@@ -50,7 +50,7 @@ var a: {
 var b: { [x: number]: string; } = { foo: '' };
 >b : { [x: number]: string; }
 >x : number
->{ foo: '' } : { [x: number]: undefined; foo: string; }
+>{ foo: '' } : { foo: string; }
 >foo : string
 >'' : string
 
diff --git a/tests/baselines/reference/objectTypesIdentityWithStringIndexers.types b/tests/baselines/reference/objectTypesIdentityWithStringIndexers.types
index a7eeb672504..8393eaf68a0 100644
--- a/tests/baselines/reference/objectTypesIdentityWithStringIndexers.types
+++ b/tests/baselines/reference/objectTypesIdentityWithStringIndexers.types
@@ -50,7 +50,7 @@ var a: {
 var b: { [x: string]: string; } = { foo: '' };
 >b : { [x: string]: string; }
 >x : string
->{ foo: '' } : { [x: string]: string; foo: string; }
+>{ foo: '' } : { foo: string; }
 >foo : string
 >'' : string
 
diff --git a/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.types b/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.types
index d1394252117..814d0c91814 100644
--- a/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.types
+++ b/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.types
@@ -64,7 +64,7 @@ var b: { [x: string]: Derived; } = { foo: <Derived>null };
 >b : { [x: string]: Derived; }
 >x : string
 >Derived : Derived
->{ foo: <Derived>null } : { [x: string]: Derived; foo: Derived; }
+>{ foo: <Derived>null } : { foo: Derived; }
 >foo : Derived
 ><Derived>null : Derived
 >Derived : Derived
diff --git a/tests/baselines/reference/operatorsAndIntersectionTypes.types b/tests/baselines/reference/operatorsAndIntersectionTypes.types
index 70611776fc1..6b5987d3a69 100644
--- a/tests/baselines/reference/operatorsAndIntersectionTypes.types
+++ b/tests/baselines/reference/operatorsAndIntersectionTypes.types
@@ -28,7 +28,7 @@ function createSerialNo() {
 let map1: { [x: string]: number } = {};
 >map1 : { [x: string]: number; }
 >x : string
->{} : { [x: string]: undefined; }
+>{} : {}
 
 let guid = createGuid();
 >guid : string & { $Guid: any; }
@@ -45,7 +45,7 @@ map1[guid] = 123;  // Can with tagged string
 let map2: { [x: number]: string } = {};
 >map2 : { [x: number]: string; }
 >x : number
->{} : { [x: number]: undefined; }
+>{} : {}
 
 let serialNo = createSerialNo();
 >serialNo : number & { $SerialNo: any; }
diff --git a/tests/baselines/reference/restElementWithNullInitializer.errors.txt b/tests/baselines/reference/restElementWithNullInitializer.errors.txt
index 7beb7b9a642..4658acc5ff4 100644
--- a/tests/baselines/reference/restElementWithNullInitializer.errors.txt
+++ b/tests/baselines/reference/restElementWithNullInitializer.errors.txt
@@ -1,6 +1,6 @@
 tests/cases/conformance/es6/destructuring/restElementWithNullInitializer.ts(1,15): error TS2461: Type 'null' is not an array type.
 tests/cases/conformance/es6/destructuring/restElementWithNullInitializer.ts(4,15): error TS2461: Type 'undefined' is not an array type.
-tests/cases/conformance/es6/destructuring/restElementWithNullInitializer.ts(7,15): error TS2461: Type '{ [x: number]: undefined; }' is not an array type.
+tests/cases/conformance/es6/destructuring/restElementWithNullInitializer.ts(7,15): error TS2461: Type '{}' is not an array type.
 
 
 ==== tests/cases/conformance/es6/destructuring/restElementWithNullInitializer.ts (3 errors) ====
@@ -16,7 +16,7 @@ tests/cases/conformance/es6/destructuring/restElementWithNullInitializer.ts(7,15
     
     function foo3([...r] = {}) {
                   ~~~~~~
-!!! error TS2461: Type '{ [x: number]: undefined; }' is not an array type.
+!!! error TS2461: Type '{}' is not an array type.
     }
     
     function foo4([...r] = []) {
diff --git a/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations.errors.txt b/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations.errors.txt
index 08881be2a86..8f4bbe2025a 100644
--- a/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations.errors.txt
+++ b/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations.errors.txt
@@ -22,10 +22,9 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerCon
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations.ts(71,5): error TS2411: Property 'foo' of type '() => string' is not assignable to string index type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations.ts(73,5): error TS2411: Property '"4.0"' of type 'number' is not assignable to string index type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations.ts(74,5): error TS2411: Property 'f' of type 'MyString' is not assignable to string index type 'string'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations.ts(78,5): error TS2322: Type '{ [x: string]: string | number | (() => void) | MyString; 1.0: string; 2.0: number; a: string; b: number; c: () => void; "d": string; "e": number; "3.0": string; "4.0": number; f: MyString; X: string; foo(): string; }' is not assignable to type '{ [x: string]: string; }'.
-  Index signatures are incompatible.
-    Type 'string | number | (() => void) | MyString' is not assignable to type 'string'.
-      Type 'number' is not assignable to type 'string'.
+tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations.ts(78,5): error TS2322: Type '{ 1.0: string; 2.0: number; a: string; b: number; c: () => void; "d": string; "e": number; "3.0": string; "4.0": number; f: MyString; X: string; foo(): string; }' is not assignable to type '{ [x: string]: string; }'.
+  Property '2.0' is incompatible with index signature.
+    Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations.ts(90,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations.ts(93,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 
@@ -158,10 +157,9 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerCon
     // error
     var b: { [x: string]: string; } = {
         ~
-!!! error TS2322: Type '{ [x: string]: string | number | (() => void) | MyString; 1.0: string; 2.0: number; a: string; b: number; c: () => void; "d": string; "e": number; "3.0": string; "4.0": number; f: MyString; X: string; foo(): string; }' is not assignable to type '{ [x: string]: string; }'.
-!!! error TS2322:   Index signatures are incompatible.
-!!! error TS2322:     Type 'string | number | (() => void) | MyString' is not assignable to type 'string'.
-!!! error TS2322:       Type 'number' is not assignable to type 'string'.
+!!! error TS2322: Type '{ 1.0: string; 2.0: number; a: string; b: number; c: () => void; "d": string; "e": number; "3.0": string; "4.0": number; f: MyString; X: string; foo(): string; }' is not assignable to type '{ [x: string]: string; }'.
+!!! error TS2322:   Property '2.0' is incompatible with index signature.
+!!! error TS2322:     Type 'number' is not assignable to type 'string'.
         a: '',
         b: 1, 
         c: () => { }, 
diff --git a/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.errors.txt b/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.errors.txt
index faef7905453..dacfb1a522d 100644
--- a/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.errors.txt
+++ b/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.errors.txt
@@ -4,8 +4,8 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerCon
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations2.ts(24,5): error TS2411: Property 'd' of type 'string' is not assignable to string index type 'A'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations2.ts(31,5): error TS2411: Property 'c' of type 'number' is not assignable to string index type 'A'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations2.ts(32,5): error TS2411: Property 'd' of type 'string' is not assignable to string index type 'A'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations2.ts(36,5): error TS2322: Type '{ [x: string]: typeof A; a: typeof A; b: typeof B; }' is not assignable to type '{ [x: string]: A; }'.
-  Index signatures are incompatible.
+tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerConstrainsPropertyDeclarations2.ts(36,5): error TS2322: Type '{ a: typeof A; b: typeof B; }' is not assignable to type '{ [x: string]: A; }'.
+  Property 'a' is incompatible with index signature.
     Type 'typeof A' is not assignable to type 'A'.
       Property 'foo' is missing in type 'typeof A'.
 
@@ -60,8 +60,8 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/stringIndexerCon
     // error
     var b: { [x: string]: A } = {
         ~
-!!! error TS2322: Type '{ [x: string]: typeof A; a: typeof A; b: typeof B; }' is not assignable to type '{ [x: string]: A; }'.
-!!! error TS2322:   Index signatures are incompatible.
+!!! error TS2322: Type '{ a: typeof A; b: typeof B; }' is not assignable to type '{ [x: string]: A; }'.
+!!! error TS2322:   Property 'a' is incompatible with index signature.
 !!! error TS2322:     Type 'typeof A' is not assignable to type 'A'.
 !!! error TS2322:       Property 'foo' is missing in type 'typeof A'.
         a: A,
diff --git a/tests/baselines/reference/stringIndexingResults.types b/tests/baselines/reference/stringIndexingResults.types
index 9f613312e5a..1fdc580b1a2 100644
--- a/tests/baselines/reference/stringIndexingResults.types
+++ b/tests/baselines/reference/stringIndexingResults.types
@@ -95,7 +95,7 @@ var r9 = a[1];
 var b: { [x: string]: string } = { y: '' }
 >b : { [x: string]: string; }
 >x : string
->{ y: '' } : { [x: string]: string; y: string; }
+>{ y: '' } : { y: string; }
 >y : string
 >'' : string
 
diff --git a/tests/baselines/reference/templateStringsArrayTypeDefinedInES5Mode.errors.txt b/tests/baselines/reference/templateStringsArrayTypeDefinedInES5Mode.errors.txt
index e6910840d39..94ab5028647 100644
--- a/tests/baselines/reference/templateStringsArrayTypeDefinedInES5Mode.errors.txt
+++ b/tests/baselines/reference/templateStringsArrayTypeDefinedInES5Mode.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/compiler/templateStringsArrayTypeDefinedInES5Mode.ts(8,3): error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'TemplateStringsArray'.
-  Property 'raw' is missing in type '{ [x: number]: undefined; }'.
+tests/cases/compiler/templateStringsArrayTypeDefinedInES5Mode.ts(8,3): error TS2345: Argument of type '{}' is not assignable to parameter of type 'TemplateStringsArray'.
+  Property 'raw' is missing in type '{}'.
 
 
 ==== tests/cases/compiler/templateStringsArrayTypeDefinedInES5Mode.ts (1 errors) ====
@@ -12,7 +12,7 @@ tests/cases/compiler/templateStringsArrayTypeDefinedInES5Mode.ts(8,3): error TS2
     
     f({}, 10, 10);
       ~~
-!!! error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'TemplateStringsArray'.
-!!! error TS2345:   Property 'raw' is missing in type '{ [x: number]: undefined; }'.
+!!! error TS2345: Argument of type '{}' is not assignable to parameter of type 'TemplateStringsArray'.
+!!! error TS2345:   Property 'raw' is missing in type '{}'.
     
     f `abcdef${ 1234 }${ 5678 }ghijkl`;
\ No newline at end of file
diff --git a/tests/baselines/reference/templateStringsArrayTypeNotDefinedES5Mode.errors.txt b/tests/baselines/reference/templateStringsArrayTypeNotDefinedES5Mode.errors.txt
index e8bf38c1048..1201c82f4d0 100644
--- a/tests/baselines/reference/templateStringsArrayTypeNotDefinedES5Mode.errors.txt
+++ b/tests/baselines/reference/templateStringsArrayTypeNotDefinedES5Mode.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/compiler/templateStringsArrayTypeNotDefinedES5Mode.ts(5,3): error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'TemplateStringsArray'.
-  Property 'raw' is missing in type '{ [x: number]: undefined; }'.
+tests/cases/compiler/templateStringsArrayTypeNotDefinedES5Mode.ts(5,3): error TS2345: Argument of type '{}' is not assignable to parameter of type 'TemplateStringsArray'.
+  Property 'raw' is missing in type '{}'.
 
 
 ==== tests/cases/compiler/templateStringsArrayTypeNotDefinedES5Mode.ts (1 errors) ====
@@ -9,7 +9,7 @@ tests/cases/compiler/templateStringsArrayTypeNotDefinedES5Mode.ts(5,3): error TS
     
     f({}, 10, 10);
       ~~
-!!! error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'TemplateStringsArray'.
-!!! error TS2345:   Property 'raw' is missing in type '{ [x: number]: undefined; }'.
+!!! error TS2345: Argument of type '{}' is not assignable to parameter of type 'TemplateStringsArray'.
+!!! error TS2345:   Property 'raw' is missing in type '{}'.
     
     f `abcdef${ 1234 }${ 5678 }ghijkl`;
\ No newline at end of file
diff --git a/tests/baselines/reference/templateStringsArrayTypeRedefinedInES6Mode.errors.txt b/tests/baselines/reference/templateStringsArrayTypeRedefinedInES6Mode.errors.txt
index ac30556a235..f410d408482 100644
--- a/tests/baselines/reference/templateStringsArrayTypeRedefinedInES6Mode.errors.txt
+++ b/tests/baselines/reference/templateStringsArrayTypeRedefinedInES6Mode.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/compiler/templateStringsArrayTypeRedefinedInES6Mode.ts(8,3): error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'TemplateStringsArray'.
-  Property 'raw' is missing in type '{ [x: number]: undefined; }'.
+tests/cases/compiler/templateStringsArrayTypeRedefinedInES6Mode.ts(8,3): error TS2345: Argument of type '{}' is not assignable to parameter of type 'TemplateStringsArray'.
+  Property 'raw' is missing in type '{}'.
 
 
 ==== tests/cases/compiler/templateStringsArrayTypeRedefinedInES6Mode.ts (1 errors) ====
@@ -12,7 +12,7 @@ tests/cases/compiler/templateStringsArrayTypeRedefinedInES6Mode.ts(8,3): error T
     
     f({}, 10, 10);
       ~~
-!!! error TS2345: Argument of type '{ [x: number]: undefined; }' is not assignable to parameter of type 'TemplateStringsArray'.
-!!! error TS2345:   Property 'raw' is missing in type '{ [x: number]: undefined; }'.
+!!! error TS2345: Argument of type '{}' is not assignable to parameter of type 'TemplateStringsArray'.
+!!! error TS2345:   Property 'raw' is missing in type '{}'.
     
     f `abcdef${ 1234 }${ 5678 }ghijkl`;
\ No newline at end of file
diff --git a/tests/baselines/reference/typeParameterFixingWithConstraints.types b/tests/baselines/reference/typeParameterFixingWithConstraints.types
index 22d294f9d2e..1e71f439e5e 100644
--- a/tests/baselines/reference/typeParameterFixingWithConstraints.types
+++ b/tests/baselines/reference/typeParameterFixingWithConstraints.types
@@ -31,17 +31,17 @@ var foo: IFoo;
 >IFoo : IFoo
 
 foo.foo({ bar: null }, bar => null, bar => null);
->foo.foo({ bar: null }, bar => null, bar => null) : { [x: string]: any; bar: any; }
+>foo.foo({ bar: null }, bar => null, bar => null) : { bar: any; }
 >foo.foo : <TBar extends IBar>(bar: TBar, bar1: (bar: TBar) => TBar, bar2: (bar: TBar) => TBar) => TBar
 >foo : IFoo
 >foo : <TBar extends IBar>(bar: TBar, bar1: (bar: TBar) => TBar, bar2: (bar: TBar) => TBar) => TBar
->{ bar: null } : { [x: string]: null; bar: null; }
+>{ bar: null } : { bar: null; }
 >bar : null
 >null : null
->bar => null : (bar: { [x: string]: any; bar: any; }) => any
->bar : { [x: string]: any; bar: any; }
+>bar => null : (bar: { bar: any; }) => any
+>bar : { bar: any; }
 >null : null
->bar => null : (bar: { [x: string]: any; bar: any; }) => any
->bar : { [x: string]: any; bar: any; }
+>bar => null : (bar: { bar: any; }) => any
+>bar : { bar: any; }
 >null : null
 
diff --git a/tests/baselines/reference/underscoreTest1.types b/tests/baselines/reference/underscoreTest1.types
index 4d8a05a5c38..37f3bdb12ab 100644
--- a/tests/baselines/reference/underscoreTest1.types
+++ b/tests/baselines/reference/underscoreTest1.types
@@ -31,7 +31,7 @@ _.each({ one: 1, two: 2, three: 3 }, (value: number, key?: string) => alert(valu
 >_.each : { <T>(list: T[], iterator: Iterator<T, void>, context?: any): void; <T>(list: Dictionary<T>, iterator: Iterator<T, void>, context?: any): void; }
 >_ : Underscore.Static
 >each : { <T>(list: T[], iterator: Iterator<T, void>, context?: any): void; <T>(list: Dictionary<T>, iterator: Iterator<T, void>, context?: any): void; }
->{ one: 1, two: 2, three: 3 } : { [x: string]: number; one: number; two: number; three: number; }
+>{ one: 1, two: 2, three: 3 } : { one: number; two: number; three: number; }
 >one : number
 >1 : number
 >two : number
@@ -68,7 +68,7 @@ _.map({ one: 1, two: 2, three: 3 }, (value: number, key?: string) => value * 3);
 >_.map : { <T, U>(list: T[], iterator: Iterator<T, U>, context?: any): U[]; <T, U>(list: Dictionary<T>, iterator: Iterator<T, U>, context?: any): U[]; }
 >_ : Underscore.Static
 >map : { <T, U>(list: T[], iterator: Iterator<T, U>, context?: any): U[]; <T, U>(list: Dictionary<T>, iterator: Iterator<T, U>, context?: any): U[]; }
->{ one: 1, two: 2, three: 3 } : { [x: string]: number; one: number; two: number; three: number; }
+>{ one: 1, two: 2, three: 3 } : { one: number; two: number; three: number; }
 >one : number
 >1 : number
 >two : number
@@ -449,7 +449,7 @@ _.size({ one: 1, two: 2, three: 3 });
 >_.size : { <T>(list: T[]): number; <T>(list: Dictionary<T>): number; }
 >_ : Underscore.Static
 >size : { <T>(list: T[]): number; <T>(list: Dictionary<T>): number; }
->{ one: 1, two: 2, three: 3 } : { [x: string]: number; one: number; two: number; three: number; }
+>{ one: 1, two: 2, three: 3 } : { one: number; two: number; three: number; }
 >one : number
 >1 : number
 >two : number
diff --git a/tests/baselines/reference/widenedTypes.errors.txt b/tests/baselines/reference/widenedTypes.errors.txt
index 2277ef6eea7..beda634c2a6 100644
--- a/tests/baselines/reference/widenedTypes.errors.txt
+++ b/tests/baselines/reference/widenedTypes.errors.txt
@@ -6,8 +6,8 @@ tests/cases/compiler/widenedTypes.ts(11,1): error TS2322: Type 'string' is not a
 tests/cases/compiler/widenedTypes.ts(18,1): error TS2322: Type 'string' is not assignable to type 'number'.
 tests/cases/compiler/widenedTypes.ts(23,5): error TS2322: Type 'number[]' is not assignable to type 'string[]'.
   Type 'number' is not assignable to type 'string'.
-tests/cases/compiler/widenedTypes.ts(24,5): error TS2322: Type '{ [x: string]: number; x: number; y: null; }' is not assignable to type '{ [x: string]: string; }'.
-  Index signatures are incompatible.
+tests/cases/compiler/widenedTypes.ts(24,5): error TS2322: Type '{ x: number; y: null; }' is not assignable to type '{ [x: string]: string; }'.
+  Property 'x' is incompatible with index signature.
     Type 'number' is not assignable to type 'string'.
 
 
@@ -52,6 +52,6 @@ tests/cases/compiler/widenedTypes.ts(24,5): error TS2322: Type '{ [x: string]: n
 !!! error TS2322:   Type 'number' is not assignable to type 'string'.
     var obj: { [x: string]: string; } = { x: 3, y: null }; // assignable because null is widened, and therefore BCT is any
         ~~~
-!!! error TS2322: Type '{ [x: string]: number; x: number; y: null; }' is not assignable to type '{ [x: string]: string; }'.
-!!! error TS2322:   Index signatures are incompatible.
+!!! error TS2322: Type '{ x: number; y: null; }' is not assignable to type '{ [x: string]: string; }'.
+!!! error TS2322:   Property 'x' is incompatible with index signature.
 !!! error TS2322:     Type 'number' is not assignable to type 'string'.
\ No newline at end of file
diff --git a/tests/baselines/reference/wrappedAndRecursiveConstraints4.errors.txt b/tests/baselines/reference/wrappedAndRecursiveConstraints4.errors.txt
index 60602351b46..47e8e6ff4f2 100644
--- a/tests/baselines/reference/wrappedAndRecursiveConstraints4.errors.txt
+++ b/tests/baselines/reference/wrappedAndRecursiveConstraints4.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/conformance/types/typeParameters/typeArgumentLists/wrappedAndRecursiveConstraints4.ts(13,12): error TS2345: Argument of type '{ [x: number]: undefined; length: number; charAt: (x: number) => void; }' is not assignable to parameter of type 'string'.
+tests/cases/conformance/types/typeParameters/typeArgumentLists/wrappedAndRecursiveConstraints4.ts(13,12): error TS2345: Argument of type '{ length: number; charAt: (x: number) => void; }' is not assignable to parameter of type 'string'.
 
 
 ==== tests/cases/conformance/types/typeParameters/typeArgumentLists/wrappedAndRecursiveConstraints4.ts (1 errors) ====
@@ -16,4 +16,4 @@ tests/cases/conformance/types/typeParameters/typeArgumentLists/wrappedAndRecursi
     var r = c.foo('');
     var r2 = r({ length: 3, charAt: (x: number) => { '' } }); // error
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ [x: number]: undefined; length: number; charAt: (x: number) => void; }' is not assignable to parameter of type 'string'.
\ No newline at end of file
+!!! error TS2345: Argument of type '{ length: number; charAt: (x: number) => void; }' is not assignable to parameter of type 'string'.
\ No newline at end of file