diff --git a/backend/services/referral-service/src/main.ts b/backend/services/referral-service/src/main.ts
index e915a2e7..814432e8 100644
--- a/backend/services/referral-service/src/main.ts
+++ b/backend/services/referral-service/src/main.ts
@@ -47,7 +47,7 @@ async function bootstrap() {
     logger.log('Swagger documentation available at /api/docs');
   }
 
-  const port = process.env.PORT || 3002;
+  const port = parseInt(process.env.APP_PORT || '3004', 10);
   await app.listen(port);
   logger.log(`Referral Service is running on port ${port}`);
 }