Upgrading from 11.0-CURRENT to 11.0-RELEASE

I'm currently running FreeBSD 11.0-CURRENT have just tried to upgrade using:

freebsd-update -r 11.0-RELEASE upgrade

Apparently you can't upgrade from a CURRENT release, so I'm wondering what my options might be... Can I install 11.0-RELEASE over my existing installation without deleting my already installed PKGs?
Ah, it should be svnlite https://svn.freebsd.org/base/releng/11.0 /usr/src/. I forgot the /usr/src/ at the end.