--- configure.ac.orig	Thu Jul 23 13:16:36 2009
+++ configure.ac	Sun Sep 13 09:30:19 2015
@@ -45,7 +45,15 @@ AC_SEARCH_LIBS(recv,socket)
 AC_CHECK_FUNCS(getopt_long)
 AC_CHECK_FUNCS(getaddrinfo)
 
-AM_PATH_LIBGNUTLS(,AC_DEFINE(HAVE_GNUTLS,,"Use libgnutls"))
+dnl Check GNU TLS
+PKG_CHECK_MODULES(GNUTLS, gnutls >= 2.0.0, have_gnutls=yes, have_gnutls=no) 
+if test "x$have_gnutls" = "xyes"; then
+  LIBGNUTLS_CFLAGS="$GNUTLS_CFLAGS"
+  LIBGNUTLS_LIBS="$GNUTLS_LIBS"
+  AC_SUBST(LIBGNUTLS_CFLAGS)
+  AC_SUBST(LIBGNUTLS_LIBS)
+  AC_DEFINE(HAVE_GNUTLS, 1, [whether to use GnuTLS support.]) 
+fi
 
 dnl Check -Wall flag of GCC
 if test "x$GCC" = "xyes"; then