The passport application of Pax. (AP)

Los Angeles, April 25 (Reuters): Film star Angelina Jolie has filed court papers to add boyfriend Brad Pitt’s last name to that of her newly adopted son, Pax, documents showed yesterday.

Jolie, who adopted Pax Thien Jolie from a Vietnamese orphanage in March, filed a petition in Los Angeles County Superior Court that would change the 3-year-old boy’s name to Pax Thien Jolie-Pitt.

The filing, a formality required to legally change the boy’s name, was first reported on the celebrity Web site TMZ.com.

Pitt has a daughter, Shiloh, with Jolie and has become the adoptive father of her other two adopted children, 5-year-old son, Maddox, from Cambodia, and 2-year-old daughter, Zahara, from Ethiopia.