diff --git a/addons/event_sale/models/sale_order.py b/addons/event_sale/models/sale_order.py
index 8c2b8bc0c3f..30c5e40d122 100644
--- a/addons/event_sale/models/sale_order.py
+++ b/addons/event_sale/models/sale_order.py
@@ -56,7 +56,7 @@ class sale_order_line(osv.osv):
         order line has a product_uom_qty attribute that will be the number of
         registrations linked to this line. This method update existing registrations
         and create new one for missing one. """
-        Registration = self.env['event.registration']
+        Registration = self.env['event.registration'].sudo()
         registrations = Registration.search([('sale_order_line_id', 'in', self.ids)])
         for so_line in [l for l in self if l.event_id]:
             existing_registrations = registrations.filtered(lambda self: self.sale_order_line_id.id == so_line.id)