diff --git a/doc/copyright.texi b/doc/copyright.texi
index 5aeb3d6d8..96e6d7da3 100644
--- a/doc/copyright.texi
+++ b/doc/copyright.texi
@@ -253,6 +253,7 @@ SUCH DAMAGE.
 vis.c in libroken
 
 @verbatim
+SPDX-License-Identifier: BSD-2-Clause
 
 Copyright (c) 1999, 2005 The NetBSD Foundation, Inc.
 All rights reserved.