diff --git a/addons/subscription/subscription.py b/addons/subscription/subscription.py
index 45916e04aee..c961e82bd5e 100644
--- a/addons/subscription/subscription.py
+++ b/addons/subscription/subscription.py
@@ -72,7 +72,7 @@ class subscription_subscription(osv.osv):
         'state': fields.selection([('draft','Draft'),('running','Running'),('done','Done')], 'Status'),
         'doc_source': fields.reference('Source Document', required=True, selection=_get_document_types, size=128, help="User can choose the source document on which he wants to create documents"),
         'doc_lines': fields.one2many('subscription.subscription.history', 'subscription_id', 'Documents created', readonly=True),
-        'cron_id': fields.many2one('ir.cron', 'Cron Job', help="Scheduler which runs on subscription"),
+        'cron_id': fields.many2one('ir.cron', 'Cron Job', help="Scheduler which runs on subscription", ondelete='cascade', states={'running':[('readonly',True)], 'done':[('readonly',True)]}),
         'note': fields.text('Notes', help="Description or Summary of Subscription"),
     }
     _defaults = {