diff --git a/LICENSE.txt b/LICENSE.txt
index e21abf6..304aadb 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -1,4 +1,4 @@
-Copyright (c) 2017-2020 Atsushi Tatsuma
+Copyright (c) 2017-2021 Atsushi Tatsuma
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without