1 files changed, 6 insertions, 2 deletions

diff --git a/gl/m4/gl-openssl.m4 b/gl/m4/gl-openssl.m4
index 7eab4e1..c5e1f7b 100644
--- a/gl/m4/gl-openssl.m4
+++ b/gl/m4/gl-openssl.m4
@@ -1,5 +1,6 @@
-# gl-openssl.m4 serial 6
-dnl Copyright (C) 2013-2023 Free Software Foundation, Inc.
+# gl-openssl.m4
+# serial 7
+dnl Copyright (C) 2013-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -39,6 +40,9 @@ AC_DEFUN([gl_CRYPTO_CHECK],
   AC_SUBST([LIB_CRYPTO])
   if test "x$with_openssl" != xno; then
     if test "x$with_openssl" = xauto-gpl-compat; then
+      dnl OpenSSL versions < 3 are under the OpenSSL license, which is not
+      dnl GPL compatible.
+      dnl See <https://www.gnu.org/licenses/license-list.en.html#OpenSSL>.
       AC_CACHE_CHECK([whether openssl is GPL compatible],
                      [gl_cv_openssl_gpl_compat],
         [AC_COMPILE_IFELSE(