diff --git a/include/gmssl/sdf.h b/include/gmssl/sdf.h
index 7ec90774..084c5379 100644
--- a/include/gmssl/sdf.h
+++ b/include/gmssl/sdf.h
@@ -1,5 +1,5 @@
 /*
- *  Copyright 2014-2023 The GmSSL Project. All Rights Reserved.
+ *  Copyright 2014-2024 The GmSSL Project. All Rights Reserved.
  *
  *  Licensed under the Apache License, Version 2.0 (the License); you may
  *  not use this file except in compliance with the License.