diff --git a/doc/copyright.texi b/doc/copyright.texi
index cae593578..af6d626de 100644
--- a/doc/copyright.texi
+++ b/doc/copyright.texi
@@ -128,6 +128,7 @@ SUCH DAMAGE.
 libedit
 
 @verbatim
+SPDX-License-Identifier: BSD-3-Clause
 
 Copyright (c) 1992, 1993
  The Regents of the University of California.  All rights reserved.