diff --git a/LICENSE.txt b/LICENSE.txt
index 5b588c6..694fc23 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2023 Atsushi Tatsuma
+Copyright (c) 2023-2024 Atsushi Tatsuma
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal