diff -r d394bfcd8c25 -r fa29f3628a1b toolsutils.py
--- a/toolsutils.py	Wed Sep 16 11:28:07 2015 +0200
+++ b/toolsutils.py	Wed Sep 16 13:57:21 2015 +0200
@@ -38,6 +38,8 @@
     def symlink(*args):
         raise NotImplementedError
 
+from six import add_metaclass
+
 from logilab.common.clcommands import Command as BaseCommand
 from logilab.common.shellutils import ASK
 
@@ -210,12 +212,13 @@
         return cls
 
 
+@add_metaclass(metacmdhandler)
 class CommandHandler(object):
     """configuration specific helper for cubicweb-ctl commands"""
-    __metaclass__ = metacmdhandler
     def __init__(self, config):
         self.config = config
 
+
 class Command(BaseCommand):
     """base class for cubicweb-ctl commands"""