diff --git a/addons/react-addons-css-transition-group/index.js b/addons/react-addons-css-transition-group/index.js
index 5d720784fb..e0524e44e7 100644
--- a/addons/react-addons-css-transition-group/index.js
+++ b/addons/react-addons-css-transition-group/index.js
@@ -1 +1,12 @@
+/**
+ * Copyright 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+'use strict';
+
 module.exports = require('react-transition-group/CSSTransitionGroup');
diff --git a/addons/react-addons-transition-group/index.js b/addons/react-addons-transition-group/index.js
index a4ba64ea43..630abb1927 100644
--- a/addons/react-addons-transition-group/index.js
+++ b/addons/react-addons-transition-group/index.js
@@ -1 +1,12 @@
+/**
+ * Copyright 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+'use strict';
+
 module.exports = require('react-transition-group/TransitionGroup');