zpool import -N mounts filesystems anyway

[Mel Pilgrim]

I need to import a pool without mounting its filesystems, but when I use 
the -N argument to zpool import to, per the man page, "Import the pool 
without mounting any file systems", it mounts the filesystems anyway.

I've tried search for an answer to this, but the question is too 
ambiguous to get a decent search result.

How do I tell ZFS to not mount anything on import?