diff --git a/old-configure.in b/old-configure.in
--- a/old-configure.in
+++ b/old-configure.in
@@ -4,10 +4,11 @@
 dnl License, v. 2.0. If a copy of the MPL was not distributed with this
 dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 dnl Process this file with autoconf to produce a configure script.
 dnl ========================================================
+AC_PREREQ(12345)
 AC_PREREQ(2.13)
 AC_INIT(config/config.mk)
 AC_CONFIG_AUX_DIR(${srcdir}/build/autoconf)
 AC_CANONICAL_SYSTEM