--- a/ForgeTracker/forgetracker/tracker_main.py
+++ b/ForgeTracker/forgetracker/tracker_main.py
@@ -1119,7 +1119,7 @@
             post = thread.add_post(text=change_text)
         else:
             post.text += '\n\n' + change_text
-            post.notify()
+            post.notify(check_dup=True)
         self.ticket.commit()
         if comment:
             self.ticket.discussion_thread.post(text=comment)