diff --git a/doc/source/conf.py b/doc/source/conf.py
index 8eaa340f5..06333cec3 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -1,9 +1,22 @@
 # -*- coding: utf-8 -*-
 
+# Copyright 2017 OpenStack Foundation.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
 import os
-import subprocess
 import sys
-import warnings
 
 sys.path.insert(0, os.path.abspath('../..'))
 # -- General configuration ----------------------------------------------------