diff --git a/examples/rag/rag_bm.py b/examples/rag/rag_bm.py
index a6a1145b5..99a546010 100644
--- a/examples/rag/rag_bm.py
+++ b/examples/rag/rag_bm.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 """RAG benchmark pipeline"""
 
 import asyncio