diff --git a/m4/update_autoconf_archive.sh b/m4/update_autoconf_archive.sh
index 0a0dd39a25..a5b955d565 100755
--- a/m4/update_autoconf_archive.sh
+++ b/m4/update_autoconf_archive.sh
@@ -1,4 +1,8 @@
 #!/bin/sh
+
+# Copyright (c) The c-ares project and its contributors
+# SPDX-License-Identifier: MIT
+
 set -e
 
 for x in `find . -name "ax_*.m4"` ; do