diff --git a/pilot/scene/chat_knowledge/v1/chat.py b/pilot/scene/chat_knowledge/v1/chat.py
index 8177a1a5a..672669a1b 100644
--- a/pilot/scene/chat_knowledge/v1/chat.py
+++ b/pilot/scene/chat_knowledge/v1/chat.py
@@ -92,7 +92,7 @@ class ChatKnowledge(BaseChat):
         context = [d.page_content for d in docs]
         context = context[: self.max_token]
         relations = list(
-            set([os.path.basename(d.metadata.get("source", "")) for d in docs])
+            set([os.path.basename(str(d.metadata.get("source", ""))) for d in docs])
         )
         input_values = {
             "context": context,