diff --git a/src/services/codefixes/helpers.ts b/src/services/codefixes/helpers.ts
index 4e91a28dafa..d3d5a46e0ec 100644
--- a/src/services/codefixes/helpers.ts
+++ b/src/services/codefixes/helpers.ts
@@ -138,7 +138,7 @@ namespace ts.codefix {
                     }
                     else {
                         Debug.assert(declarations.length === signatures.length, "Declarations and signatures should match count");
-                        addClassElement(createMethodImplementingSignatures(signatures, name, optional, modifiers, quotePreference));
+                        addClassElement(createMethodImplementingSignatures(checker, context, enclosingDeclaration, signatures, name, optional, modifiers, quotePreference));
                     }
                 }
                 break;
@@ -338,6 +338,9 @@ namespace ts.codefix {
     }
 
     function createMethodImplementingSignatures(
+        checker: TypeChecker,
+        context: TypeConstructionContext,
+        enclosingDeclaration: ClassLikeDeclaration,
         signatures: readonly Signature[],
         name: PropertyName,
         optional: boolean,
@@ -362,7 +365,6 @@ namespace ts.codefix {
         }
         const maxNonRestArgs = maxArgsSignature.parameters.length - (signatureHasRestParameter(maxArgsSignature) ? 1 : 0);
         const maxArgsParameterSymbolNames = maxArgsSignature.parameters.map(symbol => symbol.name);
-
         const parameters = createDummyParameters(maxNonRestArgs, maxArgsParameterSymbolNames, /* types */ undefined, minArgumentCount, /*inJs*/ false);
 
         if (someSigHasRestParameter) {
@@ -384,10 +386,17 @@ namespace ts.codefix {
             optional,
             /*typeParameters*/ undefined,
             parameters,
-            /*returnType*/ undefined,
+            getReturnTypeFromSignatures(signatures, checker, context, enclosingDeclaration),
             quotePreference);
     }
 
+    function getReturnTypeFromSignatures(signatures: readonly Signature[], checker: TypeChecker, context: TypeConstructionContext, enclosingDeclaration: ClassLikeDeclaration): TypeNode | undefined {
+        if (length(signatures)) {
+            const type = checker.getUnionType(map(signatures, checker.getReturnTypeOfSignature));
+            return checker.typeToTypeNode(type, enclosingDeclaration, /*flags*/ undefined, getNoopSymbolTrackerWithResolver(context));
+        }
+    }
+
     function createStubbedMethod(
         modifiers: readonly Modifier[] | undefined,
         name: PropertyName,
diff --git a/tests/cases/fourslash/codeFixClassExtendAbstractMethod.ts b/tests/cases/fourslash/codeFixClassExtendAbstractMethod.ts
index abb3f4a5703..cfab4853025 100644
--- a/tests/cases/fourslash/codeFixClassExtendAbstractMethod.ts
+++ b/tests/cases/fourslash/codeFixClassExtendAbstractMethod.ts
@@ -26,7 +26,7 @@ class C extends A {
     f(a: number, b: string): this;
     f(a: string, b: number): Function;
     f(a: string): Function;
-    f(a: any, b?: any) {
+    f(a: any, b?: any): boolean | Function | this {
         throw new Error("Method not implemented.");
     }
     foo(): number {
diff --git a/tests/cases/fourslash/codeFixClassImplementInterfaceComputedPropertyNameWellKnownSymbols.ts b/tests/cases/fourslash/codeFixClassImplementInterfaceComputedPropertyNameWellKnownSymbols.ts
index 0fc8f3767d9..163fad1cb9b 100644
--- a/tests/cases/fourslash/codeFixClassImplementInterfaceComputedPropertyNameWellKnownSymbols.ts
+++ b/tests/cases/fourslash/codeFixClassImplementInterfaceComputedPropertyNameWellKnownSymbols.ts
@@ -62,7 +62,7 @@ class C implements I<number> {
     [Symbol.toPrimitive](hint: "number"): number;
     [Symbol.toPrimitive](hint: "default"): number;
     [Symbol.toPrimitive](hint: "string"): string;
-    [Symbol.toPrimitive](hint: any) {
+    [Symbol.toPrimitive](hint: any): string | number {
         throw new Error("Method not implemented.");
     }
     [Symbol.toStringTag]: string;
diff --git a/tests/cases/fourslash/codeFixClassImplementInterfaceMethodTypePredicate.ts b/tests/cases/fourslash/codeFixClassImplementInterfaceMethodTypePredicate.ts
index 45bd6096142..f581a831cc7 100644
--- a/tests/cases/fourslash/codeFixClassImplementInterfaceMethodTypePredicate.ts
+++ b/tests/cases/fourslash/codeFixClassImplementInterfaceMethodTypePredicate.ts
@@ -18,7 +18,7 @@ verify.codeFix({
 class C implements I {
     f(i: any): i is I;
     f(): this is I;
-    f(i?: any) {
+    f(i?: any): boolean {
         throw new Error("Method not implemented.");
     }
 }`,
diff --git a/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignatures.ts b/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignatures.ts
index ddfc21615a3..f036ca38058 100644
--- a/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignatures.ts
+++ b/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignatures.ts
@@ -21,7 +21,7 @@ class C implements I {
     method(a: number, b: string): boolean;
     method(a: string, b: number): Function;
     method(a: string): Function;
-    method(a: any, b?: any) {
+    method(a: any, b?: any): boolean | Function {
         throw new Error("Method not implemented.");
     }
 }`,
diff --git a/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignaturesRest1.ts b/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignaturesRest1.ts
index 868a48711b2..b5da1ffec4c 100644
--- a/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignaturesRest1.ts
+++ b/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignaturesRest1.ts
@@ -21,7 +21,7 @@ class C implements I {
     method(a: number, ...b: string[]): boolean;
     method(a: string, ...b: number[]): Function;
     method(a: string): Function;
-    method(a: any, ...b?: any[]) {
+    method(a: any, ...b?: any[]): boolean | Function {
         throw new Error("Method not implemented.");
     }
 }`,
diff --git a/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignaturesRest2.ts b/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignaturesRest2.ts
index 29689f17ea7..c1cf60ab1bc 100644
--- a/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignaturesRest2.ts
+++ b/tests/cases/fourslash/codeFixClassImplementInterfaceMultipleSignaturesRest2.ts
@@ -21,7 +21,7 @@ class C implements I {
     method(a: number, ...b: string[]): boolean;
     method(a: string, b: number): Function;
     method(a: string): Function;
-    method(a: any, b?: any, ...rest?: any[]) {
+    method(a: any, b?: any, ...rest?: any[]): boolean | Function {
         throw new Error("Method not implemented.");
     }
 }`,