diff --git a/addons/mail/mail_thread.py b/addons/mail/mail_thread.py
index abe5c296218..972227e120f 100644
--- a/addons/mail/mail_thread.py
+++ b/addons/mail/mail_thread.py
@@ -577,7 +577,7 @@ class mail_thread(osv.Model):
         self.message_post(cr, uid, [id], message, context=context)
 
     def message_post(self, cr, uid, thread_id, body='', subject=False,
-            msg_type='notification', parent_id=False, attachments=None, context=None, **kwargs):
+            msg_type='notification', parent_id=False, attachments=None, subtype='other', context=None, **kwargs):
         """ Post a new message in an existing message thread, returning the new
             mail.message ID. Extra keyword arguments will be used as default
             column values for the new mail.message record.