diff --git a/backend/services/leaderboard-service/src/modules/domain.module.ts b/backend/services/leaderboard-service/src/modules/domain.module.ts
index 9bc19e64..907bb032 100644
--- a/backend/services/leaderboard-service/src/modules/domain.module.ts
+++ b/backend/services/leaderboard-service/src/modules/domain.module.ts
@@ -11,11 +11,11 @@ import { IdentityServiceClient } from '../infrastructure/external/identity-servi
   providers: [
     {
       provide: REFERRAL_SERVICE_CLIENT,
-      useClass: ReferralServiceClient,
+      useExisting: ReferralServiceClient,
     },
     {
       provide: IDENTITY_SERVICE_CLIENT,
-      useClass: IdentityServiceClient,
+      useExisting: IdentityServiceClient,
     },
     LeaderboardCalculationService,
     VirtualRankingGeneratorService,