diff --git a/tests/cases/compiler/contextualSignatureInstatiationContravariance.ts b/tests/cases/compiler/contextualSignatureInstatiationContravariance.ts
index 83b5cbafb6a..2bd0673abd5 100644
--- a/tests/cases/compiler/contextualSignatureInstatiationContravariance.ts
+++ b/tests/cases/compiler/contextualSignatureInstatiationContravariance.ts
@@ -5,7 +5,7 @@ interface Elephant extends Animal { y2 }
 var f2: <T extends Animal>(x: T, y: T) => void;
 
 var g2: (g: Giraffe, e: Elephant) => void;
-g2 = f2; // valid because both Giraffe and Elephant satisfy the constraint. T is Animal
+g2 = f2; // error because Giraffe and Elephant are disjoint types
 
 var h2: (g1: Giraffe, g2: Giraffe) => void;
 h2 = f2; // valid because Giraffe satisfies the constraint. It is safe in the traditional contravariant fashion.
\ No newline at end of file
diff --git a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithGenericCallSignatures2.ts b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithGenericCallSignatures2.ts
index c4904413617..e2cc7a69ee5 100644
--- a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithGenericCallSignatures2.ts
+++ b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/assignmentCompatWithGenericCallSignatures2.ts
@@ -11,6 +11,6 @@ interface B {
 var a: A;
 var b: B;
 
-// Both ok
+// Both errors
 a = b;
 b = a;
diff --git a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance2.ts b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance2.ts
index eaabadb7741..9e6cd52ac2b 100644
--- a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance2.ts
+++ b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance2.ts
@@ -61,7 +61,7 @@ interface I extends A {
     a11: <T extends Base>(x: T, y: T) => T; // ok
     a12: <T extends Array<Base>>(x: Array<Base>, y: T) => Array<Derived>; // ok, less specific parameter type
     a13: <T extends Array<Derived>>(x: Array<Base>, y: T) => T; // ok, T = Array<Derived>, satisfies constraint, contextual signature instantiation succeeds
-    a14: <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: <T, U>(x: { a: T; b: U }) => T; // ok
     a15: <T>(x: T) => T[]; // ok
     a16: <T extends Base>(x: T) => number[]; // ok
     a17: <T>(x: (a: T) => T) => T[]; // ok
diff --git a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance5.ts b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance5.ts
index b5aa243f6c1..bf60d6518cf 100644
--- a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance5.ts
+++ b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/callSignatureAssignabilityInInheritance5.ts
@@ -44,5 +44,5 @@ interface I extends B {
     a11: <T extends Base>(x: T, y: T) => T; // ok
     a12: <T extends Array<Base>>(x: Array<Base>, y: T) => Array<Derived>; // ok, less specific parameter type
     a13: <T extends Array<Derived>>(x: Array<Base>, y: T) => T; // ok, T = Array<Derived>, satisfies constraint, contextual signature instantiation succeeds
-    a14: <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: <T, U>(x: { a: T; b: U }) => T; // ok
 }
\ No newline at end of file
diff --git a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance2.ts b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance2.ts
index 2a598bb01ed..65e4f4c962e 100644
--- a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance2.ts
+++ b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance2.ts
@@ -61,7 +61,7 @@ interface I extends A {
     a11: new <T extends Base>(x: T, y: T) => T; // ok
     a12: new <T extends Array<Base>>(x: Array<Base>, y: T) => Array<Derived>; // ok, less specific parameter type
     a13: new <T extends Array<Derived>>(x: Array<Base>, y: T) => T; // ok, T = Array<Derived>, satisfies constraint, contextual signature instantiation succeeds
-    a14: new <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: new <T, U>(x: { a: T; b: U }) => T; // ok
     a15: new <T>(x: T) => T[]; // ok
     a16: new <T extends Base>(x: T) => number[]; // ok
     a17: new <T>(x: new (a: T) => T) => T[]; // ok
diff --git a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance5.ts b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance5.ts
index 43813faf8ae..f33820218ea 100644
--- a/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance5.ts
+++ b/tests/cases/conformance/types/typeRelationships/assignmentCompatibility/constructSignatureAssignabilityInInheritance5.ts
@@ -44,5 +44,5 @@ interface I extends B {
     a11: new <T extends Base>(x: T, y: T) => T; // ok
     a12: new <T extends Array<Base>>(x: Array<Base>, y: T) => Array<Derived>; // ok, less specific parameter type
     a13: new <T extends Array<Derived>>(x: Array<Base>, y: T) => T; // ok, T = Array<Derived>, satisfies constraint, contextual signature instantiation succeeds
-    a14: new <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: new <T, U>(x: { a: T; b: U }) => T; // ok
 }
\ No newline at end of file
diff --git a/tests/cases/conformance/types/typeRelationships/subtypesAndSuperTypes/subtypingWithConstructSignatures5.ts b/tests/cases/conformance/types/typeRelationships/subtypesAndSuperTypes/subtypingWithConstructSignatures5.ts
index 43813faf8ae..f33820218ea 100644
--- a/tests/cases/conformance/types/typeRelationships/subtypesAndSuperTypes/subtypingWithConstructSignatures5.ts
+++ b/tests/cases/conformance/types/typeRelationships/subtypesAndSuperTypes/subtypingWithConstructSignatures5.ts
@@ -44,5 +44,5 @@ interface I extends B {
     a11: new <T extends Base>(x: T, y: T) => T; // ok
     a12: new <T extends Array<Base>>(x: Array<Base>, y: T) => Array<Derived>; // ok, less specific parameter type
     a13: new <T extends Array<Derived>>(x: Array<Base>, y: T) => T; // ok, T = Array<Derived>, satisfies constraint, contextual signature instantiation succeeds
-    a14: new <T>(x: { a: T; b: T }) => T; // ok, best common type yields T = {} but that's satisfactory for this signature
+    a14: new <T, U>(x: { a: T; b: U }) => T; // ok
 }
\ No newline at end of file
diff --git a/tests/cases/conformance/types/typeRelationships/typeInference/contextualSignatureInstantiation.ts b/tests/cases/conformance/types/typeRelationships/typeInference/contextualSignatureInstantiation.ts
index 393d0e10d37..30c6579dabb 100644
--- a/tests/cases/conformance/types/typeRelationships/typeInference/contextualSignatureInstantiation.ts
+++ b/tests/cases/conformance/types/typeRelationships/typeInference/contextualSignatureInstantiation.ts
@@ -16,9 +16,9 @@ var a = bar(1, 1, g);      // Should be number
 var a = baz(1, 1, g);      // Should be number
 
 var b: number | string;
-var b = foo(g);            // Should be number | string
-var b = bar(1, "one", g);  // Should be number | string
-var b = bar("one", 1, g);  // Should be number | string
+var b = foo(g);            // Error, number and string are disjoint types
+var b = bar(1, "one", g);  // Error, number and string are disjoint types
+var b = bar("one", 1, g);  // Error, number and string are disjoint types
 var b = baz(b, b, g);      // Should be number | string
 
 var d: number[] | string[];