diff --git a/plugins/kolab_tags/kolab_tags.js b/plugins/kolab_tags/kolab_tags.js
index 3b1b5445..222fdf95 100644
--- a/plugins/kolab_tags/kolab_tags.js
+++ b/plugins/kolab_tags/kolab_tags.js
@@ -618,6 +618,9 @@ function message_list_update_tags(e)
 
         subject.prepend(boxes);
     });
+
+    // we don't want to do this on every listupdate event
+    rcmail.env.message_tags = null;
 }
 
 // add tags to message subject in message preview