Change default crontab editor to nano in FreeBSD

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)"