Booting in bhyve always sets currdev to ZFS

Hi,

I've installed FreeBSD current in a bhvye instance. Everything
went ok, with UFS as a root partition.
Then I created a zpool in another partition...
- Now, every time I boot it I have to
  OK set currdev=disk0s1a:
to get it to boot.

What is the trick to keep ZFS from messing up the boot variables?

Thanks, rick