Bump AC_PREREQ to 2.53.
diff --git a/configure b/configure
index 230056b..48467c9 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
#! /bin/sh
-# From configure.in Revision: 1.305 .
+# From configure.in Revision: 1.306 .
# Guess values for system-dependent variables and create Makefiles.
# Generated by GNU Autoconf 2.53.
#
diff --git a/configure.in b/configure.in
index 7f49dcc..8b04c03 100644
--- a/configure.in
+++ b/configure.in
@@ -1,6 +1,6 @@
dnl Process this file with autoconf 2.0 or later to make a configure script.
AC_REVISION($Revision$)
-AC_PREREQ(2.50)
+AC_PREREQ(2.53)
AC_INIT(Include/object.h)
AC_CONFIG_HEADER(pyconfig.h)