How do I get my iPod to play an alarm through speakers (through the headphone jack)?

I think that the iPod touch automatically plays alarms through its own speakers, even if there is something in the headphone jacks. This was probably designed so people wouldn't accidentally sleep through alarms because they left their earbuds plugged in. I want to play my alarm through my speakers to make it louder, though. Is there a way to allow an alarm to play through the headphone jack?