diff --git a/backend/apps/chat/task/llm.py b/backend/apps/chat/task/llm.py
index b208f4e2..f5d8c68d 100644
--- a/backend/apps/chat/task/llm.py
+++ b/backend/apps/chat/task/llm.py
@@ -1032,7 +1032,7 @@ class LLMService:
     def validate_history_ds(self):
         _ds = self.ds
         if not self.current_assistant:
-            current_ds = self.session.exec(CoreDatasource, _ds.id)
+            current_ds = self.session.get(CoreDatasource, _ds.id)
             if not current_ds:
                 raise Exception('ds is invalid')
         else: