diff --git a/cloudbaseinit/metadata/services/base.py b/cloudbaseinit/metadata/services/base.py
index f90d24c2..a1e0fc49 100644
--- a/cloudbaseinit/metadata/services/base.py
+++ b/cloudbaseinit/metadata/services/base.py
@@ -19,6 +19,7 @@ import time
 
 from oslo_config import cfg
 from oslo_log import log as oslo_logging
+import six
 
 from cloudbaseinit.utils import encoding
 
@@ -60,6 +61,7 @@ class NotExistingMetadataException(Exception):
     pass
 
 
+@six.add_metaclass(abc.ABCMeta)
 class BaseMetadataService(object):
     def __init__(self):
         self._cache = {}
diff --git a/cloudbaseinit/metadata/services/osconfigdrive/base.py b/cloudbaseinit/metadata/services/osconfigdrive/base.py
index fcd064fc..85685eed 100644
--- a/cloudbaseinit/metadata/services/osconfigdrive/base.py
+++ b/cloudbaseinit/metadata/services/osconfigdrive/base.py
@@ -14,7 +14,10 @@
 
 import abc
 
+import six
 
+
+@six.add_metaclass(abc.ABCMeta)
 class BaseConfigDriveManager(object):
 
     @abc.abstractmethod
diff --git a/cloudbaseinit/plugins/common/userdataplugins/base.py b/cloudbaseinit/plugins/common/userdataplugins/base.py
index 60bcc92a..d675ba29 100644
--- a/cloudbaseinit/plugins/common/userdataplugins/base.py
+++ b/cloudbaseinit/plugins/common/userdataplugins/base.py
@@ -14,7 +14,10 @@
 
 import abc
 
+import six
 
+
+@six.add_metaclass(abc.ABCMeta)
 class BaseUserDataPlugin(object):
 
     def __init__(self, mime_type):
diff --git a/cloudbaseinit/tests/metadata/services/test_baseopenstackservice.py b/cloudbaseinit/tests/metadata/services/test_baseopenstackservice.py
index d5e894fa..11df43df 100644
--- a/cloudbaseinit/tests/metadata/services/test_baseopenstackservice.py
+++ b/cloudbaseinit/tests/metadata/services/test_baseopenstackservice.py
@@ -34,11 +34,17 @@ CONF = cfg.CONF
 MODPATH = "cloudbaseinit.metadata.services.baseopenstackservice"
 
 
+class FinalBaseOpenStackService(baseopenstackservice.BaseOpenStackService):
+
+    def _get_data(self):
+        pass
+
+
 class TestBaseOpenStackService(unittest.TestCase):
 
     def setUp(self):
         CONF.set_override("retry_count_interval", 0)
-        self._service = baseopenstackservice.BaseOpenStackService()
+        self._service = FinalBaseOpenStackService()
         date = "2013-04-04"
         fake_metadata = fake_json_response.get_fake_metadata_json(date)
         self._fake_network_config = fake_metadata["network_config"]