Brad Pitt is "aware and upset" that his daughter Shiloh has dropped his name from her surname.
Shiloh filed documents last week, on her 18th birthday, to legally change her surname from Jolie-Pitt to Jolie.
"(Brad) is aware and upset that Shiloh dropped his last name," a source told People. "He's never felt more joy than when she was born. He always wanted a daughter. The reminders that he's lost his children, is of course not easy for Brad. He loves his children and misses them. It's very sad."
Brad, 60, hasn't been on good terms with his six children since he and Angelina Jolie split in 2016, after an alleged incident on a private jet.
Angelina has claimed in a lawsuit that Brad grabbed her by the head and attacked two of their children on the trip. She also alleged that he verbally abused and poured alcohol on his family during the flight from France to Los Angeles. He denies the allegations.
Brad is currently dating Ines de Ramon, but the source told People that the division from his six kids "pains him."
Another source confirmed, "He still loves all of his kids tremendously. This whole process has been very hard for the whole family."
Shiloh is the first of Brad's children to legally change her name, however others appear to have dropped Pitt from their surname too.
Vivienne, 15, is billed as Vivienne Jolie in the musical The Outsiders, while last year Zahara, 19, introduced herself as Zahara Marley Jolie in a video shared by Essence. Maddox, 22, "doesn't use Pitt as his last name on documents that aren't legal and instead uses Jolie", according to a 2021 report by US Weekly.