diff --git a/addons/mail/mail_group.py b/addons/mail/mail_group.py
index 76ce416cc77..a52f9bcab6b 100644
--- a/addons/mail/mail_group.py
+++ b/addons/mail/mail_group.py
@@ -125,7 +125,8 @@ class mail_group(osv.osv):
             type='many2many', relation='res.users', string='Group members', multi='get_member_ids',
             deprecated='This field will be deleted in a few hours or days, so please do not use it.'),
         'member_count': fields.function(get_member_ids, type='integer',
-            string='Member count', multi='get_member_ids'),
+            string='Member count', multi='get_member_ids',
+            deprecated='This field will be deleted in a few hours or days, so please do not use it.'),
         'is_subscriber': fields.function(get_member_ids, type='boolean',
             string='Joined', multi='get_member_ids'),
         'last_month_msg_nbr': fields.function(get_last_month_msg_nbr, type='integer',