updated 04/27/2010 AT 4:15 PM ET
•originally published 04/27/2010 AT 2:25 PM ET
Matt Damon and his wife Luciana are set to welcome a fourth child to the family.
Luciana, 34, is due in the fall. “Everybody’s really happy,” a rep for Damon, 39, tells PEOPLE.
The couple already have three daughters: Alexia, 11, who is Luciana’s child from a previous marriage, Isabella, who will be 4 in June, and Gia, 20 months.
Damon is a “phenomenal” father, his close friend George Clooney told PEOPLE in 2007. “He absolutely adores those kids. He’s doing it really well.”