diff --git a/addons/mail/mail_thread.py b/addons/mail/mail_thread.py
index 0753748fcd7..18486919977 100644
--- a/addons/mail/mail_thread.py
+++ b/addons/mail/mail_thread.py
@@ -1203,6 +1203,9 @@ class mail_thread(osv.AbstractModel):
         """ Add partners to the records followers. """
         if context is None:
             context = {}
+        # not necessary for computation, but saves an access right check
+        if not partner_ids:
+            return True
 
         mail_followers_obj = self.pool.get('mail.followers')
         subtype_obj = self.pool.get('mail.message.subtype')
@@ -1261,6 +1264,9 @@ class mail_thread(osv.AbstractModel):
 
     def message_unsubscribe(self, cr, uid, ids, partner_ids, context=None):
         """ Remove partners from the records followers. """
+        # not necessary for computation, but saves an access right check
+        if not partner_ids:
+            return True
         user_pid = self.pool.get('res.users').read(cr, uid, uid, ['partner_id'], context=context)['partner_id'][0]
         if set(partner_ids) == set([user_pid]):
             self.check_access_rights(cr, uid, 'read')