diff --git a/product/ERP5OOo/Document/OOoDocument.py b/product/ERP5OOo/Document/OOoDocument.py
index 248718b637668fae691ffbf11696ab381ebf989a..d90426fd36dee84280997a684ee98d62e2439351 100644
--- a/product/ERP5OOo/Document/OOoDocument.py
+++ b/product/ERP5OOo/Document/OOoDocument.py
@@ -140,6 +140,7 @@ class OOoDocument(PermanentURLMixIn, File, ConversionCacheMixin):
                     , PropertySheet.ExternalDocument
                     , PropertySheet.Url
                     , PropertySheet.Periodicity
+                    , PropertySheet.SortIndex
                     )
 
   # regular expressions for stripping xml from ODF documents