diff --git a/src/pipecat/services/llm_service.py b/src/pipecat/services/llm_service.py
index 70164ebd8..45be7ee74 100644
--- a/src/pipecat/services/llm_service.py
+++ b/src/pipecat/services/llm_service.py
@@ -408,7 +408,7 @@ class LLMService(AIService):
             function_name: The name of the function handler to remove.
         """
         del self._functions[function_name]
-        if self._start_callbacks[function_name]:
+        if function_name in self._start_callbacks:
             del self._start_callbacks[function_name]
 
     def unregister_direct_function(self, handler: Any):