Angular Interceptors are overwritten and disappear

Question

I have a core module in which I define two HTTP interceptors. Like this:

@NgModule({
    imports: [...],
    declarations: [...],
    exports: [...],
    providers: [
        { provide: HTTP_INTERCEPTORS, useClass: BasicAuthInterceptor, multi: true },
        { provide: HTTP_INTERCEPTORS, useClass: CoreInterceptor, multi: true },
        ...
    ],
})
export class CoreModule {}

This works well. The interceptors are called in my entire application and do their job. Now I wanted to extend a module of my application with another interceptor.

@NgModule({
    imports: [...],
    declarations: [...],
    exports: [...],
    providers: [
        { provide: HTTP_INTERCEPTORS, useClass: EventInterceptor, multi: true },
        ...
    ],
})
export class ApplicationModule {}

As soon as I include the EventInterceptor, the interceptors from my CoreModule are no longer called. Of course I could now also include BasicAuthInterceptor and CoreInterceptor in my ApplicationModule. However, I would like to avoid that. What am I doing wrong?