diff --git a/hbmqtt/plugins/topic_checking.py b/hbmqtt/plugins/topic_checking.py
index 19e5e5a..ce80816 100644
--- a/hbmqtt/plugins/topic_checking.py
+++ b/hbmqtt/plugins/topic_checking.py
@@ -28,7 +28,7 @@ class TopicTabooPlugin(BaseTopicPlugin):
         if filter_result:
             session = kwargs.get('session', None)
             topic = kwargs.get('topic', None)
-            if session.username and topic:
+            if topic:
                 if session.username != 'admin' and topic in self._taboo:
                     return False
                 return True