Change default crontab editor to nano in FreeBSD

Warning: WP_Syntax::substituteToken(): Argument #1 ($match) must be passed by reference, value given in /var/www/vhosts/ on line 383

When I edit the crontab using crontab -e it opens the crontab in vi. I’d prefer it to use nano. How can I change this?

# Every time when a unixsoftware starts an editor, it tries it with $EDITOR e.g.
# crontab -e
#export EDITOR=vi
export EDITOR="$(which nano)"