diff --git a/index.d.ts b/index.d.ts
index 4b860763f2..8b3a05e394 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,3 +1,5 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
 import * as chromium from './chromium';
 import * as firefox from './firefox';
 import * as webkit from './webkit';