--- xdg-user-dirs-0.18/configure.ac
+++ xdg-user-dirs-0.18/configure.ac
@@ -1,26 +1,29 @@
-AC_INIT(xdg-user-dirs-update.c)
+AC_INIT
+AC_CONFIG_SRCDIR([xdg-user-dirs-update.c])
 
-AM_INIT_AUTOMAKE(xdg-user-dirs, 0.18)
-AM_CONFIG_HEADER(config.h)
+AM_INIT_AUTOMAKE([xdg-user-dirs], [0.18])
+AM_CONFIG_HEADER([config.h])
 
 AM_SANITY_CHECK
 AM_MAINTAINER_MODE
 
 AC_C_CONST
-AC_ISC_POSIX
+AC_SEARCH_LIBS([strerror],[cposix])
 AC_PROG_CC
 AC_PROG_CPP
 AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
-AM_PROG_MKDIR_P
+AC_PROG_MKDIR_P
 AM_ICONV
 
 GETTEXT_PACKAGE=xdg-user-dirs
 AC_DEFINE_UNQUOTED(GETTEXT_PACKAGE,"$GETTEXT_PACKAGE", [The gettext domain name])
 AC_SUBST(GETTEXT_PACKAGE)
 
+AC_CONFIG_MACRO_DIR([m4])
 AM_GNU_GETTEXT([external])
+AM_GNU_GETTEXT_VERSION([0.22])
 
 dnl ==========================================================================
 dnl Turn on the additional warnings last, so -Werror doesn't affect other tests.
@@ -50,9 +53,7 @@
 		SAVE_CFLAGS="$CFLAGS"
 		CFLAGS="$CFLAGS $option"
 		AC_MSG_CHECKING([whether gcc understands $option])
-		AC_TRY_COMPILE([], [],
-			has_option=yes,
-			has_option=no,)
+		AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[]])],[has_option=yes],[has_option=no])
 		if test $has_option = no; then
 			CFLAGS="$SAVE_CFLAGS"
 		fi
@@ -66,8 +67,7 @@
 fi
 
 AC_ARG_ENABLE(documentation,
-              AC_HELP_STRING([--enable-documentation],
-                             [build documentation]),,
+              AS_HELP_STRING([--enable-documentation],[build documentation]),,
               enable_documentation=yes)
 if test x$enable_documentation = xyes; then
    AC_PATH_PROG([XSLTPROC], [xsltproc])
@@ -77,7 +77,8 @@
 fi
 AM_CONDITIONAL(BUILD_DOCUMENTATION, test x$enable_documentation = xyes)
 
-AC_OUTPUT([ po/Makefile.in
+AC_CONFIG_FILES([ po/Makefile.in
 Makefile
 man/Makefile
 ])
+AC_OUTPUT