Solved freebsd-update and /usr/src

I have a few FreeBSD 10.1 Release droplets in the Digital Ocean Cloud. None of them have /usr/src installed by default and it's unnecessary anyway because I'm using freebsd-update.

This morning freebsd-update fetch found a whole bunch of files in /usr/src/contrib to update. The files were fetched and then there followed screens of "no such file or directory" errors. freebsd-version -u showed "10.1-RELEASE-p23" but the next run of freebsd-update fetch found and downloaded all the "missing" files again.

So, is there any way to EXCLUDE /usr/src? To date, I've been creating the missing directories to keep freebsd-update happy.
Excellent. Thank You. That'll teach me to not read all the command man pages even if they don't seem relevant!