Typescript with RxJS filter typing problem

Question

I've just upgraded from typescript 2.4 to 3.2 and now with the unknown type, the type system is stricter which trigger some errors that I didn't have before.

So I have an effect that retreive some possibly null data from the store and I want to make sure its not null by using a filter before dispatching my next action.

@Effect() saveSuccess$: Observable<Action> = this.actions$.pipe(
        ofType(actions.SAVE_SUCCESS),
        switchMapTo(this.store.pipe(select(selectors.getId))),
        filter((id: number | null) => id !== null),
        map((id: number) => new actions.GetData({ Id }))
);

The filter is now red saying:

    Argument of type 'MonoTypeOperatorFunction<number | null>' is not assignable to parameter of type 'OperatorFunction<number | null, number>'.
  Type 'Observable<number | null>' is not assignable to type 'Observable<number>'.
    Type 'number | null' is not assignable to type 'number'.
      Type 'null' is not assignable to type 'number'.ts(2345)

I can bypass the error by using any type but I feel like I shouldn't. If I change the map to accept number | null it works but it makes no sens since its exactly the filter's job.