upgrading a pair or 13.5 firewall to 14.3

Hello,

I have a pair of firewall (running pf, pfsync, carp, lagg, vlan) which are still running 13.5-RELEASE. I'd like to upgrade to 14.3-RELEASE and I was wondering what would be the best procedure as I rememberd that there are some pfsync protocol changes in 14.3 (which are incompatible with the one in 13.5) ..?

Can I simply start by upgrading the BACKUP node to 14.3 and update rc.conf with pfsync_ifconfig="version 1301" and then update the MASTER?

Thanks!

Julien