diff --git a/samples/python/src/roles/merchant_agent/agent_executor.py b/samples/python/src/roles/merchant_agent/agent_executor.py
index 55cc43e9..d1a4d42a 100644
--- a/samples/python/src/roles/merchant_agent/agent_executor.py
+++ b/samples/python/src/roles/merchant_agent/agent_executor.py
@@ -97,7 +97,7 @@ async def _handle_request(
 
   async def _validate_shopping_agent(
       self, data_parts: list[dict[str, Any]], updater: TaskUpdater
-  ) -> None:
+  ) -> bool:
     """Validates that the incoming request is from a trusted Shopping Agent.
 
     Args: