diff --git a/configure.ac b/configure.ac
index 2f59066..a9654cb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-# $Id: configure.ac,v 1.320 2006/01/01 08:47:05 djm Exp $
+# $Id: configure.ac,v 1.321 2006/01/01 10:03:30 djm Exp $
 #
 # Copyright (c) 1999-2004 Damien Miller
 #
@@ -328,7 +328,7 @@
 	esac
 	# tun(4) forwarding compat code
 	AC_CHECK_HEADERS(linux/if_tun.h)
-	if test "x$ac_cv_header_linux_tun_h" = "xyes" ; then
+	if test "x$ac_cv_header_linux_if_tun_h" = "xyes" ; then
 		AC_DEFINE(SSH_TUN_LINUX, 1,
 		    [Open tunnel devices the Linux tun/tap way])
 		AC_DEFINE(SSH_TUN_COMPAT_AF, 1,