Hollywood superstar couple Angelina Jolie and Brad Pitt have officially adopted 4-year-old Pax Thien from Vietnam.

A Los Angeles County Children's Court judge finalized the couple's adoption of Pax on Wednesday, a spokesperson for Jolie confirmed to People.com Friday.

The 4-year-old boy has lived with the couple and their three other children for nearly a year.

He is now a legally recognized member of the ever-growing family, which in addition to the celebrity parents includes fellow siblings Maddox, 6; Zahara, 3; and Shiloh, who turns 2 in May.

TMZ.com reported Thursday that the happy family held a mini celebration after the judge signed off on the paperwork at a courthouse in the Monterey Park area of L.A.

Jolie adopted Pax from an orphanage in Vietnam last year, saying at the time, "You can imagine what courage it takes to be in all new surroundings, with new people and a new language. He is very strong."

While an official adoption ceremony did take place in Vietnam's Department of Justice in March 2007, the U.S. had not, until now, formalized the addition.