diff --git a/CHANGES.rst b/CHANGES.rst
index 5c3721c4..aa4910f0 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -14,7 +14,10 @@ New features:
 
 Bug fixes:
 
-- *add item here*
+- Use the _marker from CMFCore for MemberDataTool.getProperty,
+  this makes sure that we never return the _marker from PlonePAS
+  but an error.
+  [pcdummy]
 
 
 5.0.10 (2016-05-02)
diff --git a/src/Products/PlonePAS/tools/memberdata.py b/src/Products/PlonePAS/tools/memberdata.py
index 3115f8fc..fda3f218 100644
--- a/src/Products/PlonePAS/tools/memberdata.py
+++ b/src/Products/PlonePAS/tools/memberdata.py
@@ -4,6 +4,7 @@
 from Acquisition import aq_base
 from App.class_init import InitializeClass
 from Products.BTreeFolder2.BTreeFolder2 import BTreeFolder2
+from Products.CMFCore.MemberDataTool import _marker
 from Products.CMFCore.MemberDataTool import MemberData as BaseMemberData
 from Products.CMFCore.MemberDataTool import MemberDataTool as BaseTool
 from Products.CMFCore.permissions import ManagePortal
@@ -23,8 +24,6 @@
     IRoleAssignerPlugin
 from zope.interface import implementer
 
-_marker = object()
-
 
 class MemberDataTool(BaseTool):
     """PAS-specific implementation of memberdata tool.