diff --git a/product/ERP5/Document/Document.py b/product/ERP5/Document/Document.py
index 1d51a3d26c0ef227070edc2af8ecd355fcb9583d..8a4c172b93da82e2800cbe7ded9c6e181b835fcd 100644
--- a/product/ERP5/Document/Document.py
+++ b/product/ERP5/Document/Document.py
@@ -42,7 +42,7 @@ from Products.ERP5Type.Utils import convertToUpperCase
 from Products.ERP5Type.Base import WorkflowMethod
 from Products.ERP5Type.TransactionalVariable import getTransactionalVariable
 from Products.ERP5Type.ExtensibleTraversable import ExtensibleTraversableMixIn
-from Products.ERP5Type.Cache import getReadOnlyTransactionCache, DEFAULT_CACHE_SCOPE
+from Products.ERP5Type.Cache import getReadOnlyTransactionCache
 from Products.ERP5.Document.Url import UrlMixIn
 from Products.ERP5.Tool.ContributionTool import MAX_REPEAT
 from Products.ERP5Type.UnrestrictedMethod import UnrestrictedMethod
@@ -62,11 +62,6 @@ VALID_ORDER_KEY_LIST = ('user_login', 'content', 'file_name', 'input')
 # these property ids are unchangable
 FIXED_PROPERTY_IDS =  ('id', 'uid', 'rid', 'sid')
 
-def makeSortedTuple(kw):
-  items = kw.items()
-  items.sort()
-  return tuple(items)
-
 class SnapshotMixin:
   """
     This class provides a generic API to store in the ZODB
diff --git a/product/ERP5/mixin/cached_convertable.py b/product/ERP5/mixin/cached_convertable.py
index f35fb5e93c3dd49573aced14766c00c9dbf4de26..0dbcb54226e5331bd70c34cae20ef4d6424d4f6b 100644
--- a/product/ERP5/mixin/cached_convertable.py
+++ b/product/ERP5/mixin/cached_convertable.py
@@ -34,6 +34,11 @@ from Products.ERP5Type import Permissions
 from Products.CMFCore.utils import getToolByName
 from Products.ERP5Type.Cache import DEFAULT_CACHE_SCOPE
 
+def makeSortedTuple(kw):
+  items = kw.items()
+  items.sort()
+  return tuple(items)
+
 class CachedConvertableMixin:
   """
   This class provides a generic implementation of IConvertable.