diff --git a/protobuf/lib/src/protobuf/message_set.dart b/protobuf/lib/src/protobuf/message_set.dart
index 23b9bdad2..ba9664d64 100644
--- a/protobuf/lib/src/protobuf/message_set.dart
+++ b/protobuf/lib/src/protobuf/message_set.dart
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.