diff --git a/dbgpt/serve/rag/retriever/retriever_chain.py b/dbgpt/serve/rag/retriever/retriever_chain.py
index 88c8b8a0b..65d8ce91e 100644
--- a/dbgpt/serve/rag/retriever/retriever_chain.py
+++ b/dbgpt/serve/rag/retriever/retriever_chain.py
@@ -46,9 +46,7 @@ async def _aretrieve(
             List[Chunk]: list of chunks
         """
         for retriever in self._retrievers:
-            candidates = await retriever.aretrieve(
-                query=query, filters=filters
-            )
+            candidates = await retriever.aretrieve(query=query, filters=filters)
             if candidates:
                 return candidates
         return []