diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index 4f7e89ae26b..af32d394332 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -175,10 +175,10 @@ class MailThread(models.AbstractModel):
                              RIGHT JOIN mail_channel_partner cp
                              ON (cp.channel_id = rel.mail_channel_id AND cp.partner_id = %s AND
                                 (cp.seen_message_id IS NULL OR cp.seen_message_id < msg.id))
-                             WHERE msg.model = %s AND msg.res_id in %s AND
+                             WHERE msg.model = %s AND msg.res_id = ANY(%s) AND
                                    (msg.author_id IS NULL OR msg.author_id != %s) AND
                                    (msg.message_type != 'notification' OR msg.model != 'mail.channel')""",
-                         (partner_id, self._name, tuple(self.ids), partner_id,))
+                         (partner_id, self._name, list(self.ids), partner_id,))
         for result in self._cr.fetchall():
             res[result[0]] += 1