--- a/m4/getopt.m4
+++ b/m4/getopt.m4
@@ -1,13 +1,47 @@
-# getopt.m4 serial 2
-dnl Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+# getopt.m4 serial 3
+dnl Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
 dnl This file is free software, distributed under the terms of the GNU
 dnl General Public License.  As a special exception to the GNU General
 dnl Public License, this file may be distributed as part of a program
 dnl that contains a configuration script generated by Autoconf, under
 dnl the same distribution terms as the rest of that program.
 
+# The getopt module assume you want GNU getopt, with getopt_long etc,
+# rather than vanilla POSIX getopt.  This means your your code should
+# always include <getopt.h> for the getopt prototypes.
+
+AC_DEFUN([gl_GETOPT_SUBSTITUTE],
+[
+  GETOPT_H=getopt.h
+  AC_LIBOBJ([getopt])
+  AC_LIBOBJ([getopt1])
+  AC_DEFINE([optarg], [rpl_optarg],
+    [Define to rpl_optarg if the replacement variable should be used.])
+  AC_DEFINE([optind], [rpl_optind],
+    [Define to rpl_optind if the replacement variable should be used.])
+  AC_DEFINE([optopt], [rpl_optopt],
+    [Define to rpl_optopt if the replacement variable should be used.])
+  AC_DEFINE([getopt], [rpl_getopt],
+    [Define to rpl_getopt if the replacement function should be used.])
+  AC_DEFINE([getopt_long], [rpl_getopt_long],
+    [Define to rpl_getopt_long if the replacement function should be used.])
+  AC_DEFINE([getopt_long_only], [rpl_getopt_long_only],
+    [Define to rpl_getopt_long_only if the replacement function should be used.])
+  AC_SUBST([GETOPT_H])
+])
+
 AC_DEFUN([gl_GETOPT],
 [
-  dnl Prerequisites of lib/getopt.c.
-  :
+  gl_PREREQ_GETOPT
+
+  GETOPT_H=
+  AC_CHECK_HEADERS([getopt.h], [], [GETOPT_H=getopt.h])
+  AC_CHECK_FUNCS([getopt_long_only], [], [GETOPT_H=getopt.h])
+
+  if test -n "$GETOPT_H"; then
+     gl_GETOPT_SUBSTITUTE
+  fi
 ])
+
+# Prerequisites of lib/getopt*.
+AC_DEFUN([gl_PREREQ_GETOPT], [:])