diff --git a/src/shared/modules/offer/offer-service.interface.ts b/src/shared/modules/offer/offer-service.interface.ts
index 0394c16..d49f4dd 100644
--- a/src/shared/modules/offer/offer-service.interface.ts
+++ b/src/shared/modules/offer/offer-service.interface.ts
@@ -13,5 +13,6 @@ export interface OfferService {
   incCommentCount(offerId: string): Promise<DocumentType<OfferEntity> | null>;
   exists(documentId: string): Promise<boolean>;
   findFavorite(count: number): Promise<DocumentType<OfferEntity>[]>;
-  findPremium(count: number): Promise<DocumentType<OfferEntity>[]>
+  findPremium(count: number): Promise<DocumentType<OfferEntity>[]>;
+  calculateRating(offerId: string, newRating: number): Promise<DocumentType<OfferEntity> | null>;
 }