diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index 766c7175201..a0264dee89e 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -251,6 +251,8 @@ class purchase_order(osv.osv):
         for po in self.browse(cr, uid, ids):
             if self.pool.get('res.partner.event.type').check(cr, uid, 'purchase_open'):
                 self.pool.get('res.partner.event').create(cr, uid, {'name':'Purchase Order: '+po.name, 'partner_id':po.partner_id.id, 'date':time.strftime('%Y-%m-%d %H:%M:%S'), 'user_id':uid, 'partner_type':'retailer', 'probability': 1.0, 'planned_cost':po.amount_untaxed})
+            if not po.order_line:
+                raise osv.except_osv(_('Error !'),_('You can not confirm purchase order without Purchase Order Lines.'))
         current_name = self.name_get(cr, uid, ids)[0][1]
         for id in ids:
             self.write(cr, uid, [id], {'state' : 'confirmed', 'validator' : uid})