diff --git a/product/ERP5/Document/PaymentCondition.py b/product/ERP5/Document/PaymentCondition.py
index 9d5e929ddc9cf4f70dc014a78665bbd71d12ea2f..593078f5b3c63c5a4e1f64e56d24e5b39d07a3ce 100644
--- a/product/ERP5/Document/PaymentCondition.py
+++ b/product/ERP5/Document/PaymentCondition.py
@@ -54,5 +54,6 @@ class PaymentCondition(XMLObject):
                       , PropertySheet.DublinCore
                       , PropertySheet.Amount
                       , PropertySheet.PaymentCondition
+                      , PropertySheet.SortIndex
                       )