diff --git a/addons/mail/res_partner.py b/addons/mail/res_partner.py
index aeec9a5a6b3..3dc1f91d857 100644
--- a/addons/mail/res_partner.py
+++ b/addons/mail/res_partner.py
@@ -33,7 +33,7 @@ class res_partner_mail(osv.osv):
         """
         initial_domain = super(res_partner_mail, self).message_search_get_domain(cr, uid, ids, context=context)
         if self._name == 'res.partner': # to avoid models inheriting from res.partner
-            search_domain = ['|'] + initial_domain + [('partner_ids', 'in', ids)]
+            search_domain = ['|'] + initial_domain + ['|', ('partner_id', 'in', ids), ('partner_ids', 'in', ids)]
         return search_domain
 
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