[Exim] Command line option for Subject?

Greetings:

Anyone know the command line parameter for Exim to specify subject?
I'm trying to mail a report from cron thusly:

cat report | /usr/sbin/exim -s "Daily Report" username

Exim complains about '-s'. If I drop '-s "Daily Report"' then the
report is mailed okay (with no subject line, tho).

TIA