diff --git a/addons/mail/models/mail_notification.py b/addons/mail/models/mail_notification.py
index 51db4cbfc7b..daa88004c6a 100644
--- a/addons/mail/models/mail_notification.py
+++ b/addons/mail/models/mail_notification.py
@@ -49,13 +49,10 @@ class MailNotification(models.Model):
     ]
 
     def init(self):
-        self._cr.execute('SELECT indexname FROM pg_indexes WHERE indexname = %s',
-                         ('mail_notification_res_partner_id_is_read_notification_status_mail_message_id',))
-        if not self._cr.fetchone():
-            self._cr.execute("""
-                CREATE INDEX mail_notification_res_partner_id_is_read_notification_status_mail_message_id
-                          ON mail_notification (res_partner_id, is_read, notification_status, mail_message_id)
-            """)
+        self._cr.execute("""
+            CREATE INDEX IF NOT EXISTS mail_notification_res_partner_id_is_read_notification_status_mail_message_id
+                                    ON mail_notification (res_partner_id, is_read, notification_status, mail_message_id)
+        """)
 
     @api.model_create_multi
     def create(self, vals_list):