--- nmap/configure.ac

+++ nmap/configure.ac

@@ -531,6 +531,9 @@ AC_HELP_STRING([--with-libdnet=included], [Use the libdnet version included with

     ;;

   included)

     ;;

+  /usr)

+    have_dnet=yes

+    ;;

   *)

     CPPFLAGS="-I$with_libdnet/include $CPPFLAGS"

     LDFLAGS="-L$with_libdnet/lib $LDFLAGS"