diff --git a/product/ERP5/Document/Document.py b/product/ERP5/Document/Document.py
index df44a511409265ca00c55c73df92343afadb5200..b3a92b81da6ddc3419aa23a47b2450e2b7e64af6 100644
--- a/product/ERP5/Document/Document.py
+++ b/product/ERP5/Document/Document.py
@@ -36,7 +36,7 @@ from Acquisition import aq_base
 from Products.ERP5Type.Accessor.Constant import PropertyGetter as ConstantGetter
 from Products.ERP5Type.Globals import get_request
 from Products.CMFCore.utils import getToolByName, _checkPermission
-from Products.ERP5Type import Permissions, PropertySheet, Constraint, interfaces
+from Products.ERP5Type import Permissions, PropertySheet, interfaces
 from Products.ERP5Type.XMLObject import XMLObject
 from Products.ERP5Type.DateUtils import convertDateToHour, number_of_hours_in_day, number_of_hours_in_year
 from Products.ERP5Type.Utils import convertToUpperCase
@@ -51,7 +51,6 @@ from Products.ZSQLCatalog.SQLCatalog import SQLQuery
 from AccessControl import Unauthorized
 import zope.interface
 import cStringIO
-import string
 from OFS.Image import Pdata
 from Products.PythonScripts.Utility import allow_class