diff --git a/README.md b/README.md
index 80f31b6..1684e5e 100644
--- a/README.md
+++ b/README.md
@@ -173,7 +173,7 @@ License
 ========
 
 ```
-Copyright 2022-2023 ARIYAMA Keiji
+Copyright 2022-2024 ARIYAMA Keiji
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.