diff --git a/lib/set.rb b/lib/set.rb
index 374c45b19a..46c212beae 100644
--- a/lib/set.rb
+++ b/lib/set.rb
@@ -3,7 +3,7 @@
 #
 # set.rb - defines the Set class
 #
-# Copyright (c) 2002-2023 Akinori MUSHA <knu@iDaemons.org>
+# Copyright (c) 2002-2024 Akinori MUSHA <knu@iDaemons.org>
 #
 # Documentation by Akinori MUSHA and Gavin Sinclair.
 #