Error Providing Service in Lazy Loaded Module (Angular 6)

I have a lazy loaded module (LazyModule) and a service to be provided in its scope (LazyModuleService).

When using @Injectable({providedIn: LazyModule}) for the LazyModuleService class, Angular compiler throws a No Provider error as soon as I inject LazyModuleService in any child component of LazyModule.

However, when I remove {providedIn: LazyModule} from the decorator and instead add providers: [LazyModuleService] to the @NgModule decorator of LazyModule, my app compiles and works without errors or warnings.

According to the relevant section of, both solutions should work, not just the latter.

Please advice.