Angelina Jolie with sons Pax and MaddoxAngelina Jolie and Brad Pitt have formally finalised the adoption of their son Pax Thien Jolie-Pitt.

Angelina took custody of the boy in Vietnam last March as a single parent because under Vietnamese law, unmarried couples can not make joint adoption applications. However, a month later, they filed papers at a court in Los Angeles to change the boy’s surname to “Jolie-Pitt” to reflect Brad’s role in his life.

Now the adoption has been finalised at the US end by the Los Angeles County Children’s Court in Monterey Park, California.

A source close to the family said: “To them, it’s just paperwork because he’s been a part of the family from day one but they’re still glad it’s sorted.”