diff --git a/handler/agora.py b/handler/agora.py
index 46b21de..a89d153 100644
--- a/handler/agora.py
+++ b/handler/agora.py
@@ -149,7 +149,7 @@ class Agora(object):
         if send_irc:
             if reference in self.last_messages:
                 if not len(self.last_messages[reference]) == len(messages_tmp):
-                    difference = set(messages_tmp) ^ self.last_messages[reference]
+                    difference = set(messages_tmp) ^ set(self.last_messages[reference])
                     for x in difference:
                         self.irc.client.msg(self.irc.client.channel, f"AUTO {reference}: {x}")
             else: