Update copyrights
diff --git a/src/csharp/Grpc.Core/AsyncAuthInterceptor.cs b/src/csharp/Grpc.Core/AsyncAuthInterceptor.cs
index 5ba06d6..1ad2290 100644
--- a/src/csharp/Grpc.Core/AsyncAuthInterceptor.cs
+++ b/src/csharp/Grpc.Core/AsyncAuthInterceptor.cs
@@ -1,6 +1,6 @@
 #region Copyright notice and license
 
-// Copyright 2015-2016, Google Inc.
+// Copyright 2015, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without