MutationAction not working with RemoteData union type

[FranzBusch]

I am trying to use vuex-module-decotrators in conjunction with union types like RemoteData; however, I am getting a type error when doing so. My RemoteData union type looks like this

export type NotAsked = {
    type: "NotAsked";
}
  
  export type Loading = {
    type: "Loading";
  }
  
  export type Success<T> = {
    type: "Success";
    data: T;
  }
  
  export type Failure<E> = {
    type: "Failure";
    error: E;
  }
  
  export type RemoteData<T, E> = Success<T> | NotAsked | Loading | Failure<E>;

And my usage inside a store looks like this

@Module({
  namespaced: true,
  dynamic: true,
  store: store,
  name: 'foo',
})
class FooModule extends VuexModule {
  bar: RemoteData<string, UserError> = Success("");

  @MutationAction
  async getBar() {
    return {
      bar: NotAsked
    }
  }
}

The type error I am seeing is this:

Type 'RemoteData<string, UserError>' is not assignable to type 'NotAsked | null'.

Is there anything I can do with vuex-module-decorators to make this work?