diff --git a/socketio/asyncio_namespace.py b/socketio/asyncio_namespace.py
index ba22e4e5..893c5e01 100644
--- a/socketio/asyncio_namespace.py
+++ b/socketio/asyncio_namespace.py
@@ -36,7 +36,7 @@ async def trigger_event(self, event, *args):
                 try:
                     ret = await handler(*args)
                 except asyncio.CancelledError:  # pragma: no cover
-                    pass
+                    ret = None
             else:
                 ret = handler(*args)
             return ret