diff --git a/addons/sale/sale.py b/addons/sale/sale.py
index c0cf12fa371..1318e63b230 100644
--- a/addons/sale/sale.py
+++ b/addons/sale/sale.py
@@ -619,6 +619,8 @@ class sale_order(osv.osv):
 
     def action_wait(self, cr, uid, ids, *args):
         for o in self.browse(cr, uid, ids):
+            if not o.order_line:
+                raise osv.except_osv(_('Error !'),_('You cannot confirm a sale order which has no line.'))
             if (o.order_policy == 'manual'):
                 self.write(cr, uid, [o.id], {'state': 'manual', 'date_confirm': time.strftime(DEFAULT_SERVER_DATE_FORMAT)})
             else: