diff --git a/src/lib/services/entities-map.service.ts b/src/lib/services/entities-map.service.ts
index 1ecdf26..6f79db8 100644
--- a/src/lib/services/entities-map.service.ts
+++ b/src/lib/services/entities-map.service.ts
@@ -6,10 +6,8 @@ import { List, RequiredParam, shareLast, Validate } from '../utils';
 import { Id } from '../listing/models/trackable';
 import { isArray } from '../permissions';
 
-@Injectable({ providedIn: 'root' })
+@Injectable()
 export abstract class EntitiesMapService<Interface, Class extends Entity<Interface, PrimaryKey>, PrimaryKey extends Id = Class['id']> {
-    protected abstract readonly _primaryKey: string;
-
     protected readonly _map = new Map<Id, BehaviorSubject<Class[]>>();
     readonly #entityChanged$ = new Subject<Class>();
     readonly #entitiesChanged$ = new BehaviorSubject<boolean>(false);
@@ -48,8 +46,8 @@ export abstract class EntitiesMapService<Interface, Class extends Entity<Interfa
     }
 
     get(key: Id): Class[];
-    get(key: Id, id: Id): Class | undefined;
-    get(key: Id, id?: Id): Class | Class[] | undefined {
+    get(key: Id, id: PrimaryKey): Class | undefined;
+    get(key: Id, id?: PrimaryKey): Class | Class[] | undefined {
         const value = this._getBehaviourSubject(key)?.value;
         if (!id) {
             return value ?? [];
@@ -119,8 +117,7 @@ export abstract class EntitiesMapService<Interface, Class extends Entity<Interfa
         return false;
     }
 
-    @Validate()
-    watch$(@RequiredParam() key: Id, @RequiredParam() entityId: Id): Observable<Class> {
+    watch$(key: string, @RequiredParam() entityId: PrimaryKey): Observable<Class> {
         return this.#entityChanged$.pipe(
             filter(entity => entity.id === entityId),
             startWith(this.get(key, entityId) as Class),
@@ -138,7 +135,7 @@ export abstract class EntitiesMapService<Interface, Class extends Entity<Interfa
         );
     }
 
-    watchDeleted$(entityId: Id): Observable<Class> {
+    watchDeleted$(entityId: PrimaryKey): Observable<Class> {
         return this.#entityDeleted$.pipe(filter(entity => entity.id === entityId));
     }