--- a/__init__.py	Wed Sep 16 14:45:15 2015 +0200
+++ b/__init__.py	Mon Sep 14 12:19:48 2015 +0200
@@ -22,7 +22,6 @@
 
 # ignore the pygments UserWarnings
 import warnings
-import cPickle
 import zlib
 warnings.filterwarnings('ignore', category=UserWarning,
                         message='.*was already imported',
@@ -40,6 +39,8 @@
 import sys, os, logging
 from StringIO import StringIO
 
+from six.moves import cPickle as pickle
+
 from logilab.common.deprecation import deprecated
 from logilab.common.logging_ext import set_log_methods
 from yams.constraints import BASE_CONVERTERS, BASE_CHECKERS
@@ -132,12 +133,12 @@
     def zpickle(cls, obj):
         """ return a Binary containing a gzipped pickle of obj """
         retval = cls()
-        retval.write(zlib.compress(cPickle.dumps(obj, protocol=2)))
+        retval.write(zlib.compress(pickle.dumps(obj, protocol=2)))
         return retval
 
     def unzpickle(self):
         """ decompress and loads the stream before returning it """
-        return cPickle.loads(zlib.decompress(self.getvalue()))
+        return pickle.loads(zlib.decompress(self.getvalue()))
 
 
 def check_password(eschema, value):