diff --git a/lightrag/kg/postgres_impl.py b/lightrag/kg/postgres_impl.py
index 2d249e05..11b71284 100644
--- a/lightrag/kg/postgres_impl.py
+++ b/lightrag/kg/postgres_impl.py
@@ -345,7 +345,7 @@ class PGKVStorage(BaseKVStorage):
     async def get_by_mode_and_id(self, mode: str, id: str) -> Union[dict, None]:
         """Specifically for llm_response_cache."""
         sql = SQL_TEMPLATES["get_by_mode_id_" + self.namespace]
-        params = {"workspace": self.db.workspace, mode: mode, "id": id}
+        params = {"workspace": self.db.workspace, "mode": mode, "id": id}
         if is_namespace(self.namespace, NameSpace.KV_STORE_LLM_RESPONSE_CACHE):
             array_res = await self.db.query(sql, params, multirows=True)
             res = {}