2 files changed, 6 insertions, 4 deletions
diff --git a/nova/keymgr/key.py b/nova/keymgr/key.py
index 644cf34c4d..8f9903e23e 100644
--- a/nova/keymgr/key.py
+++ b/nova/keymgr/key.py
@@ -25,12 +25,13 @@ from Java.
 
 import abc
 
+import six
 
+
+@six.add_metaclass(abc.ABCMeta)
 class Key(object):
     """Base class to represent all keys."""
 
-    __metaclass__ = abc.ABCMeta
-
     @abc.abstractmethod
     def get_algorithm(self):
         """Returns the key's algorithm.
diff --git a/nova/keymgr/key_mgr.py b/nova/keymgr/key_mgr.py
index bd5669fa56..b47c79e905 100644
--- a/nova/keymgr/key_mgr.py
+++ b/nova/keymgr/key_mgr.py
@@ -20,7 +20,10 @@ Key manager API
 
 import abc
 
+import six
 
+
+@six.add_metaclass(abc.ABCMeta)
 class KeyManager(object):
     """Base Key Manager Interface
 
@@ -28,8 +31,6 @@ class KeyManager(object):
     Key Manager is responsible for creating, reading, and deleting keys.
     """
 
-    __metaclass__ = abc.ABCMeta
-
     @abc.abstractmethod
     def create_key(self, ctxt, algorithm='AES', length=256, expiration=None,
                    **kwargs):