[chef] berksfile.lock versioning, can i switch from librarian yet?

[Jesse Campbell < >]

In librarian, I can create a Cheffile.lock and test it on the dev
environment, then check it into version control, push to production,
and librarian-chef will strictly follow the lock file for what gets
installed.

In berkshelf, I can create a Berksfile.lock and test it on the dev
environment, then check it into version control, push to production,
and berkshelf will sometimes follow the lockfile, and sometimes to
whatever the fuck it wants and install newer versions of things like
apache2 that I haven't tested yet.

What am I doing wrong? Is there no option for berkshelf to strictly
follow the locksfile? Is it always just a suggestion?