diff --git a/README.md b/README.md
index fca76f6..5243141 100644
--- a/README.md
+++ b/README.md
@@ -51,4 +51,4 @@ Licensed under the GNU Public License (GPL) version 2
 More infomation is available:
   * https://www.dokuwiki.org/plugin:pagetitle
 
-(c) 2014-2019 Satoshi Sahara \<sahara.satoshi@gmail.com>
+(c) 2014-2023 Satoshi Sahara \<sahara.satoshi@gmail.com>