nfsdがインストールされて起動しているのにエラーが出ます。どうしたらよいでしょうか。

$vagrant up
Bringing machine 'default' up with 'virtualbox' provider...
==> default: Checking if box 'xxxxxxxx' is up to date...
It appears your machine doesn't support NFS, or there is not an
adapter to enable NFS on this machine for Vagrant. Please verify
that `nfsd` is installed on your machine, and try again. If you're
on Windows, NFS isn't supported. If the problem persists, please
contact Vagrant support.

起動確認

$ /sbin/nfsd status
nfsd service is enabled
nfsd is running (pid 1333, 8 threads)

環境

Vagrant 1.8.1
Mac OSX Yosemite
VirtualBox 4.2.12