diff -urNp -x '*.orig' postgresql-12.17.org/configure.in postgresql-12.17/configure.in
--- postgresql-12.17.org/configure.in	2023-12-16 01:43:48.648048213 +0100
+++ postgresql-12.17/configure.in	2023-12-16 01:43:51.721087441 +0100
@@ -19,10 +19,6 @@ m4_pattern_forbid(^PGAC_)dnl to catch un
 
 AC_INIT([PostgreSQL], [12.18], [pgsql-bugs@lists.postgresql.org])
 
-m4_if(m4_defn([m4_PACKAGE_VERSION]), [2.69], [], [m4_fatal([Autoconf version 2.69 is required.
-Untested combinations of 'autoconf' and PostgreSQL versions are not
-recommended.  You can remove the check from 'configure.in' but it is then
-your responsibility whether the result works or not.])])
 AC_COPYRIGHT([Copyright (c) 1996-2019, PostgreSQL Global Development Group])
 AC_CONFIG_SRCDIR([src/backend/access/common/heaptuple.c])
 AC_CONFIG_AUX_DIR(config)