diff --git a/api/core/agent/cot_agent_runner.py b/api/core/agent/cot_agent_runner.py
index 12554f42b3..ff45474680 100644
--- a/api/core/agent/cot_agent_runner.py
+++ b/api/core/agent/cot_agent_runner.py
@@ -189,7 +189,7 @@ class CotAgentRunner(BaseAgentRunner, ABC):
 
             if not scratchpad.action:
                 # failed to extract action, return final answer directly
-                final_answer = scratchpad.agent_response or ''
+                final_answer = ''
             else:
                 if scratchpad.action.action_name.lower() == "final answer":
                     # action is final answer, return final answer directly