diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 0f057e61667..e2b7efeac67 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -79,6 +79,7 @@ namespace ts {
             getIndexTypeOfType,
             getBaseTypes,
             getReturnTypeOfSignature,
+            getNonNullableType,
             getSymbolsInScope,
             getSymbolAtLocation,
             getShorthandAssignmentValueSymbol,
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 3a5602717c1..d924ac168c8 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -1770,6 +1770,7 @@ namespace ts {
         getIndexTypeOfType(type: Type, kind: IndexKind): Type;
         getBaseTypes(type: InterfaceType): ObjectType[];
         getReturnTypeOfSignature(signature: Signature): Type;
+        getNonNullableType(type: Type): Type;
 
         getSymbolsInScope(location: Node, meaning: SymbolFlags): Symbol[];
         getSymbolAtLocation(node: Node): Symbol;
diff --git a/src/services/services.ts b/src/services/services.ts
index 39dd688254d..d8abb4e6842 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -50,6 +50,7 @@ namespace ts {
         getStringIndexType(): Type;
         getNumberIndexType(): Type;
         getBaseTypes(): ObjectType[];
+        getNonNullableType(): Type;
     }
 
     export interface Signature {
@@ -735,6 +736,9 @@ namespace ts {
                 ? this.checker.getBaseTypes(<InterfaceType><Type>this)
                 : undefined;
         }
+        getNonNullableType(): Type {
+            return this.checker.getNonNullableType(this);
+        }
     }
 
     class SignatureObject implements Signature {
@@ -4366,7 +4370,7 @@ namespace ts {
                         (location.kind === SyntaxKind.ConstructorKeyword && location.parent.kind === SyntaxKind.Constructor)) { // At constructor keyword of constructor declaration
                         // get the signature from the declaration and write it
                         const functionDeclaration = <FunctionLikeDeclaration>location.parent;
-                        const allSignatures = functionDeclaration.kind === SyntaxKind.Constructor ? type.getConstructSignatures() : type.getCallSignatures();
+                        const allSignatures = functionDeclaration.kind === SyntaxKind.Constructor ? type.getNonNullableType().getConstructSignatures() : type.getNonNullableType().getCallSignatures();
                         if (!typeChecker.isImplementationOfOverload(functionDeclaration)) {
                             signature = typeChecker.getSignatureFromDeclaration(functionDeclaration);
                         }
@@ -4541,10 +4545,8 @@ namespace ts {
                         }
 
                         // For properties, variables and local vars: show the type
-                        // Also handle methods that have a union type (i.e. that may be undefined)
                         if (symbolKind === ScriptElementKind.memberVariableElement ||
                             symbolFlags & SymbolFlags.Variable ||
-                            symbolFlags & SymbolFlags.Method && type.flags & TypeFlags.Union ||
                             symbolKind === ScriptElementKind.localVariableElement ||
                             isThisExpression) {
                             displayParts.push(punctuationPart(SyntaxKind.ColonToken));
@@ -4566,7 +4568,7 @@ namespace ts {
                             symbolFlags & SymbolFlags.Signature ||
                             symbolFlags & SymbolFlags.Accessor ||
                             symbolKind === ScriptElementKind.memberFunctionElement) {
-                            const allSignatures = type.getCallSignatures();
+                            const allSignatures = type.getNonNullableType().getCallSignatures();
                             addSignatureDisplayParts(allSignatures[0], allSignatures);
                         }
                     }