Angular 2 RC6: 'pattern-list' is not a known element

Simply running the application I get no error and it works just fine, but when I run my tests I get the following error:

'pattern-list' is not a known element:
  1. If 'pattern-list' is an Angular component, then verify that it is part of this module.
  2. If 'pattern-list' is a Web Component then add "CUSTOM_ELEMENTS_SCHEMA" to the '@NgModule.schema' of this component to suppress this message. ("
         [ERROR ->]<pattern-list></pattern-list>

I had this issue first when I just run the application with 'npm-start' and I solved it adding the required component to app.module in the declarations section. But now as I want to test I get the same error and I don't know why. Here is my code:

app.module.ts

@NgModule({
  imports: [ BrowserModule, FormsModule, HttpModule, ReactiveFormsModule ],
  declarations: [ AppComponent, PatternListComponent, PatternDetailComponent, WidgetListComponent,
    FormComponent, DefaultWidget, LabelComponent, CheckboxWidget ],
  bootstrap: [ AppComponent ],
  providers: [ WidgetService ]
})
export class AppModule { }

app.component.ts

@Component({
     selector: 'my-app',
     template: `
           <pattern-list></pattern-list>
          `
    })
    export class AppComponent { }

My test file: app.component.spec.ts
describe('AppComponent with TCB', function () {
  beforeEach(() => {
    TestBed.configureTestingModule({declarations: [AppComponent]});
  });
  describe('asdfasdf', function () {
    beforeEach(async(() => {
      TestBed.compileComponents();
    }));
    it('should instantiate component', () => {
      let fixture = TestBed.createComponent(AppComponent);
      expect(fixture.componentInstance instanceof AppComponent).toBe(true, 'should create AppComponent');
    });
  });
});

I'm using webpack, I'm not sure if that matters.