Jason and Mandy Castro

American Idol alum Jason Castro is going to be a dad.

The dreadlocked Season 7 finalist and his wife, Mandy Mayhall, are expecting a daughter in August, he announced on his website.

American Idol's Jason Castro marries

"We just found out yesterday that it is going to be a girl!" Castro wrote. "haha that makes me laugh... what am i going to do with a sweet little girl?! probably just smile alot... i cannot wait!!!"

The 24-year-old also posted a photo of Mayhall's sonogram, under the caption "Baby Castro!!"

Castro and Mayhall wed in January 2010.