diff --git a/expandybird/expansion/references.py b/expandybird/expansion/references.py
index 6fc46c09a..f35c7d246 100644
--- a/expandybird/expansion/references.py
+++ b/expandybird/expansion/references.py
@@ -1,3 +1,15 @@
+######################################################################
+# Copyright 2015 The Kubernetes Authors 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.
+######################################################################
 """Util to handle references during expansion."""
 
 import jsonpath