diff --git a/product/ERP5Type/ZopePatch.py b/product/ERP5Type/ZopePatch.py
index 7e8b99e207c04e43594c101eab58207be70886e2..79b2f9783035151f8c96e1f49b30f02f664add7d 100644
--- a/product/ERP5Type/ZopePatch.py
+++ b/product/ERP5Type/ZopePatch.py
@@ -52,6 +52,7 @@ from Products.ERP5Type.patches import Connection
 from Products.ERP5Type.patches import copy_reg_patch
 from Products.ERP5Type.patches import PersistencePatch
 from Products.ERP5Type.patches import PersistentMapping
+from Products.ERP5Type.patches import DateTimePatch
 
 # for python2.3 compatibility
 import threading
diff --git a/product/ERP5Type/patches/DateTimePatch.py b/product/ERP5Type/patches/DateTimePatch.py
new file mode 100644
index 0000000000000000000000000000000000000000..79784efc8465f030e395342b3b93c2c1fd2eae82
--- /dev/null
+++ b/product/ERP5Type/patches/DateTimePatch.py
@@ -0,0 +1,45 @@
+##############################################################################
+#
+# Copyright (c) 2007 Nexedi SARL and Contributors. All Rights Reserved.
+#                    Vincent Pelletier <vincent@nexedi.com>
+#
+# WARNING: This program as such is intended to be used by professional
+# programmers who take the whole responsability of assessing all potential
+# consequences resulting from its eventual inadequacies and bugs
+# End users who are looking for a ready-to-use solution with commercial
+# garantees and support are strongly adviced to contract a Free Software
+# Service Company
+#
+# This program is Free Software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+#
+##############################################################################
+
+from DateTime import DateTime as DateTimeKlass
+
+STATE_KEY = 'str'
+
+def DateTime__setstate__(self, state):
+  if len(state) != 1 or STATE_KEY not in state:
+    # For backward compatibility
+    self.__dict__.update(state)
+  else:
+    self._parse_args(state[STATE_KEY])
+
+DateTimeKlass.__setstate__ = DateTime__setstate__
+  
+def DateTime__getstate__(self):
+  return {STATE_KEY: str(self)}
+
+DateTimeKlass.__getstate__ = DateTime__getstate__