diff --git a/addon/doc/en/readme.md b/addon/doc/en/readme.md
index 9e4d321..0875493 100644
--- a/addon/doc/en/readme.md
+++ b/addon/doc/en/readme.md
@@ -86,7 +86,7 @@ You can change the setting by selecting "Upside Braille-Down" from the NVDA menu
 
 ## 5. Copyright
 
-(c) 2021 Hiroki Fujii - ACT Laboratory
+(c) 2024 Hiroki Fujii - ACT Laboratory
 
 GNU General Public License, version 2
 
diff --git a/addon/doc/ja/readme.md b/addon/doc/ja/readme.md
index 7f9b00c..ae66907 100644
--- a/addon/doc/ja/readme.md
+++ b/addon/doc/ja/readme.md
@@ -86,7 +86,7 @@ NVDAメニューから「Upside Braille-Down」を選択し、「起動時のア
 
 ## 5. 著作権
 
-(c) 2021 Hiroki Fujii - ACT Laboratory
+(c) 2024 Hiroki Fujii - ACT Laboratory
 
 GNU General Public License, version 2