diff --git a/autobahn/wamp/component.py b/autobahn/wamp/component.py
index d9bf13d97..6175c73e5 100644
--- a/autobahn/wamp/component.py
+++ b/autobahn/wamp/component.py
@@ -668,7 +668,7 @@ def transport_check(_):
     def stop(self):
         self._stopping = True
         if self._session and self._session.is_attached():
-            self._session.leave()
+            return self._session.leave()
         elif self._delay_f:
             # This cancel request will actually call the "error" callback of
             # the _delay_f future. Nothing to worry about.