Ali Larter visited 'Late Night with Jimmy Fallon' on Thursday and confirmed that her unborn child will be a boy. Fallon offered her a choice of a pink or blue onesie, and she chose the blue one.
"I was trying to keep it private, but we're having a boy!" she said. "I have a little penis inside of me."
Ali's son will be her first child with husband Hayes MacArthur.
See photos of Ali showing off her big baby bump last week here.WATCH: