$NetBSD: patch-ah,v 1.3 2008/03/08 01:06:52 tnn Exp $

--- src/df.c.orig	2008-01-11 14:47:21.000000000 +0100
+++ src/df.c
@@ -944,8 +944,10 @@ main (int argc, char **argv)
 	     _("cannot read table of mounted file systems"));
     }
 
+#if HAVE_SYNC
   if (require_sync)
     sync ();
+#endif
 
   if (optind < argc)
     {