diff --git a/product/ERP5/Document/OrderBuilder.py b/product/ERP5/Document/OrderBuilder.py
index 1b8fc8d547b91e3288a52295f4d424dd94bf1cbb..11b5c9b8376cd393b39bf20077c75a8fad196cde 100755
--- a/product/ERP5/Document/OrderBuilder.py
+++ b/product/ERP5/Document/OrderBuilder.py
@@ -200,7 +200,7 @@ class OrderBuilder(XMLObject, Amount, Predicate):
 #                               section_uid=self.getDestinationSectionUid())
           max_delay = resource.getMaxDelay(0)
           movement.edit(
-            start_date=DateTime((stop_date-max_delay.Date())),
+            start_date=DateTime(((stop_date-max_delay).Date())),
             stop_date=DateTime(stop_date.Date()),
             quantity=min_flow-inventory_item.inventory,
             quantity_unit=resource.getQuantityUnit()