diff --git a/api/core/memory/read_only_conversation_token_db_buffer_shared_memory.py b/api/core/memory/read_only_conversation_token_db_buffer_shared_memory.py
index 4123521ae3fae9..9840c5c22da5c3 100644
--- a/api/core/memory/read_only_conversation_token_db_buffer_shared_memory.py
+++ b/api/core/memory/read_only_conversation_token_db_buffer_shared_memory.py
@@ -27,7 +27,7 @@ def buffer(self) -> List[BaseMessage]:
         # fetch limited messages desc, and return reversed
         messages = db.session.query(Message).filter(
             Message.conversation_id == self.conversation.id,
-            Message.answer_tokens > 0
+            Message.answer != ''
         ).order_by(Message.created_at.desc()).limit(self.message_limit).all()
 
         messages = list(reversed(messages))