diff --git a/openerp/addons/base/ir/ir_rule.py b/openerp/addons/base/ir/ir_rule.py
index 0626b2b9c1e..6b069e0b9d0 100644
--- a/openerp/addons/base/ir/ir_rule.py
+++ b/openerp/addons/base/ir/ir_rule.py
@@ -75,7 +75,7 @@ class ir_rule(osv.osv):
 
     _columns = {
         'name': fields.char('Name', size=128, select=1),
-        'model_id': fields.many2one('ir.model', 'Object',select=1, required=True),
+        'model_id': fields.many2one('ir.model', 'Object',select=1, required=True, ondelete="cascade"),
         'global': fields.function(_get_value, string='Global', type='boolean', store=True, help="If no group is specified the rule is global and applied to everyone"),
         'groups': fields.many2many('res.groups', 'rule_group_rel', 'rule_group_id', 'group_id', 'Groups'),
         'domain_force': fields.text('Domain'),