diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index ded3d3cd3a3..d6c1d4c903f 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -241,7 +241,7 @@ class purchase_order(osv.osv):
             if s['state'] in ['draft','cancel']:
                 unlink_ids.append(s['id'])
             else:
-                raise osv.except_osv(_('Invalid action !'), _('In order to delete a purchase order, it must be cancelled first! ')  % _(dict(purchase_order.STATE_SELECTION).get(s['state'])))
+                raise osv.except_osv(_('Invalid action !'), _('In order to delete a purchase order, it must be cancelled first!'))
 
         # TODO: temporary fix in 5.0, to remove in 5.2 when subflows support
         # automatically sending subflow.delete upon deletion