diff --git a/fastapi_book_server/app/services/common.py b/fastapi_book_server/app/services/common.py
index 945721d..0d5460d 100644
--- a/fastapi_book_server/app/services/common.py
+++ b/fastapi_book_server/app/services/common.py
@@ -76,7 +76,7 @@ class BaseService(Generic[MODEL, QUERY], abc.ABC):
 
             await p.delete(key)
             await p.set(active_key, 1, ex=cls.CACHE_TTL)
-            await p.rpush(key, *object_ids)
+            await p.sadd(key, *object_ids)
 
             await p.execute()