diff --git a/packages/core/src/render3/metadata.ts b/packages/core/src/render3/metadata.ts
index bfa8e65a64..053d742845 100644
--- a/packages/core/src/render3/metadata.ts
+++ b/packages/core/src/render3/metadata.ts
@@ -28,7 +28,7 @@ export function setClassMetadata(
     propDecorators: {[field: string]: any} | null): void {
   const clazz = type as TypeWithMetadata;
   if (decorators !== null) {
-    if (clazz.decorators !== undefined) {
+    if (clazz.hasOwnProperty('decorators') && clazz.decorators !== undefined) {
       clazz.decorators.push(...decorators);
     } else {
       clazz.decorators = decorators;
diff --git a/packages/core/test/test_bed_spec.ts b/packages/core/test/test_bed_spec.ts
index 0492ecd2c0..2b055bc58d 100644
--- a/packages/core/test/test_bed_spec.ts
+++ b/packages/core/test/test_bed_spec.ts
@@ -48,8 +48,21 @@ export class SimpleCmp {
 export class WithRefsCmp {
 }
 
+@Component({selector: 'inherited-cmp', template: 'inherited'})
+export class InheritedCmp extends SimpleCmp {
+}
+
+@Component({
+  selector: 'simple-app',
+  template: `
+    <simple-cmp></simple-cmp> - <inherited-cmp></inherited-cmp>
+  `
+})
+export class SimpleApp {
+}
+
 @NgModule({
-  declarations: [HelloWorld, SimpleCmp, WithRefsCmp],
+  declarations: [HelloWorld, SimpleCmp, WithRefsCmp, InheritedCmp, SimpleApp],
   imports: [GreetingModule],
   providers: [
     {provide: NAME, useValue: 'World!'},
@@ -174,6 +187,13 @@ describe('TestBed', () => {
     expect(hello.nativeElement).toHaveText('Hello injected World !');
   });
 
+  it('should resolve components that are extended by other components', () => {
+    // SimpleApp uses SimpleCmp in its template, which is extended by InheritedCmp
+    const simpleApp = TestBed.createComponent(SimpleApp);
+    simpleApp.detectChanges();
+    expect(simpleApp.nativeElement).toHaveText('simple - inherited');
+  });
+
   onlyInIvy('patched ng defs should be removed after resetting TestingModule')
       .it('make sure we restore ng defs to their initial states', () => {
         @Pipe({name: 'somePipe', pure: true})
diff --git a/packages/core/testing/src/resolvers.ts b/packages/core/testing/src/resolvers.ts
index 2a15dd7bc5..bacbe78273 100644
--- a/packages/core/testing/src/resolvers.ts
+++ b/packages/core/testing/src/resolvers.ts
@@ -37,7 +37,9 @@ abstract class OverrideResolver<T> implements Resolver<T> {
   }
 
   getAnnotation(type: Type<any>): T|null {
-    return reflection.annotations(type).find(a => a instanceof this.type) || null;
+    // We should always return the last match from filter(), or we may return superclass data by
+    // mistake.
+    return reflection.annotations(type).filter(a => a instanceof this.type).pop() || null;
   }
 
   resolve(type: Type<any>): T|null {