diff --git a/stack/erp5/buildout.cfg b/stack/erp5/buildout.cfg
index 7987edaaaad6bedbff2aa244e700083bb392e443..316b261feab48ac49c908a8d63883779fdca4a88 100644
--- a/stack/erp5/buildout.cfg
+++ b/stack/erp5/buildout.cfg
@@ -19,7 +19,7 @@ allow-hosts += pybrary.net
 
 extends =
 # Exact version of Zope
-  https://raw.github.com/zopefoundation/Zope/2.13.22/versions.cfg
+  https://raw.github.com/zopefoundation/Zope/2.12.28/versions.cfg
   ../../stack/slapos.cfg
   ../../component/logrotate/buildout.cfg
   ../../component/cups/buildout.cfg
@@ -49,7 +49,6 @@ extends =
   ../../component/pil-python/buildout.cfg
   ../../component/pycrypto-python/buildout.cfg
   ../../component/pysvn-python/buildout.cfg
-  ../../component/python-2.7/buildout.cfg
   ../../component/python-ldap-python/buildout.cfg
   ../../component/rdiff-backup/buildout.cfg
   ../../component/stunnel/buildout.cfg
@@ -418,16 +417,12 @@ recipe = minitage.recipe.egg
 eggs =
   Acquisition
   Products.DCWorkflow
-  ZODB3
 Acquisition-patches = ${:_profile_base_location_}/../../component/egg-patch/Acquisition/aq_dynamic.patch
 Acquisition-patch-options = -p1
 Acquisition-patch-binary = ${patch:location}/bin/patch
 Products.DCWorkflow-patches = ${:_profile_base_location_}/../../component/egg-patch/Products.DCWorkflow/workflow_method.patch
 Products.DCWorkflow-patch-options = -p1
 Products.DCWorkflow-patch-binary = ${patch:location}/bin/patch
-ZODB3-patches = ${:_profile_base_location_}/../../component/egg-patch/ZODB3-3.10.5.patch
-ZODB3-patch-options = -p1
-ZODB3-patch-binary = ${patch:location}/bin/patch
 
 [eggs]
 recipe = zc.recipe.egg
@@ -506,10 +501,6 @@ eggs =
   Products.TIDStorage
   Products.LongRequestLogger
 
-# BBB: Temporarily keep zope.app.testing awaiting we use newer version of CMF
-#      (for tests like testCookieCrumbler).
-  zope.app.testing
-
 # Currently forked in our repository
 #    Products.PortalTransforms
 # Dependency for our fork of PortalTransforms
@@ -562,7 +553,6 @@ scripts =
 # patched eggs
 Acquisition = 2.13.8-ZMinitagePatched-AqDynamic
 Products.DCWorkflow = 2.2.4-ZMinitagePatched-WorkflowMethod
-ZODB3 = 3.10.5-ZMinitagePatched-ZODB33105
 
 # specify dev version to be sure that an old released version is not used
 cloudooo = 1.2.5-dev
@@ -612,15 +602,6 @@ Products.CMFDefault = 2.2.4
 Products.CMFTopic = 2.2.1
 Products.CMFUid = 2.2.1
 
-# newer version requires zope.traversing>=4.0.0a2.
-zope.app.appsetup = 3.16.0
-
-# newer version requires zope.i18n>=4.0.0a3
-zope.app.publication = 3.14.0
-
-# newer version requires zope.testbrowser>=4
-zope.app.testing = 3.8.1
-
 # Pinned versions
 Flask = 0.10.1
 GitPython = 0.3.2.RC1
@@ -717,6 +698,3 @@ uuid = 1.30
 validictory = 0.9.3
 xml-marshaller = 0.9.7
 xupdate-processor = 0.4
-zope.app.debug = 3.4.1
-zope.app.dependable = 3.5.1
-zope.app.form = 4.0.2
diff --git a/stack/slapos.cfg b/stack/slapos.cfg
index 80c2bc0f569873f484befadf3063c3d4d7f79ed7..4ea24c863e855d2e2d6e51209f5fd69c3f81a53c 100644
--- a/stack/slapos.cfg
+++ b/stack/slapos.cfg
@@ -2,7 +2,7 @@
 # Software Releases or Stacks can safely extend this stack.
 
 [buildout]
-python = python2.7
+python = python2.6
 
 # Developers need to add explicitely this part in their software profile
 # parts = slapos-cookbook
@@ -16,7 +16,7 @@ extensions +=
 
 # Use shacache and lxml
 extends =
-  ../component/python-2.7/buildout.cfg
+  ../component/python-2.6/buildout.cfg
   ../component/lxml-python/buildout.cfg
   ../component/python-cffi/buildout.cfg
   ../component/python-cryptography/buildout.cfg