Josh Hartnett is going to be a dad!

Looks like dating this co-star was no mistake for Josh Hartnett!

The Black Hawk Down star and his girlfriend, Tamsin Egerton, are expecting a baby, his rep confirms to ET.

PHOTOS: Baby Bumps to Watch This Summer

Hartnett reportedly met the 26-year-old British actress on the set of The Lovers in 2011, and they began dating in 2012, according to Page Six.

The 36-year-old actor recently admitted to having babies on the brain. While discussing working in Hollywood and money with Playboyrecently, he said, "If we could just help one another and express ourselves, we'd all be happy. But then I think, 'Oh shit, there are bills to be paid, and I'd have to get a car that's safe for my kid.' I don't have a kid yet, but that's the idea coming into my head these days."

NEWS: Josh Hartnett Talks 'Mistakes' of Dating Co-Stars in the Past

Well, now it really is time to pick out that car seat!

Hartnett, who is currently starring in Penny Dreadful, previously dated co-stars Scarlett Johansson, Kirsten Dunst, Julia Stiles and Amanda Seyfried.

See which other celebs are expecting in the video below.