Apparently, Brad Pitt isn't too thrilled that his daughter, Shiloh, dropped his last name.

PEOPLE reports that the actor wasn't happy when he learned about the decision from the daughter he shared with his ex, Angelina Jolie. It sounds like it was probably heartbreaking for him.

Brad Pitt's daughter makes a name change

This all stems from Monday, May 27, when, on her 18th birthday, she decided to file documents requesting a new legal last name. She'd like to go by Shiloh Jolie from now on.

A source said, “He's aware and upset that Shiloh dropped his last name. 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,” the source continued. “He loves his children and misses them. It's very sad.”

Another source told PEOPLE, “He still loves all of his kids tremendously. This whole process has been very hard for the whole family.”

Shiloh is not the only child the famous actor has with Jolie. They also have Maddox (22), Zahara (19), Pax (2o), and twins Knox and Vivienne (15). Beyond that, a few others have made a similar request to drop Pitt.

Vivienne has also requested that her name be changed, but, as far as the public knows, not in a legal manner. In the recent Playbill for The Outsiders, which the daughter helped produce, she's listed as Vivienne Jolie instead of Vivienne Jolie-Pitt. Also, last November, Zahara introduced herself as Zahara Marley Jolie when she joined the Mu Pi chapter of the Alpha Kappa Alpha sorority at Spelman College.

So, what happened? What's the deal with the name changes?

Many of the children seem upset with Brad. Though we don't live under their roofs, this could be caused by a lack of correspondence or because he's not around much. Most of the strain on their relationship started when he lost physical custody in 2016 after Jolie filed for divorce.

“Since Angelina filed for divorce, Brad has been focused on having the best relationship possible with his kids,” an insider said. “It's been very difficult for him. Many times, there have been long gaps where he didn't see the kids at all.”

According to Today, in 2018, Jolie's attorney stated that Pitt had “paid no meaningful child support since separation.” Also, arrangements around the children's expenses have been “informal” and indicated that Jolie wanted to get a “retroactive child support order.”

Other tensions have existed between Brad and Angelina. One was the sale of her interest in a winery they had purchased together.

Vanity Fair states that she wrote, “Even now, impossible to write this without crying. Above all, it is the place we brought the twins home to and where we were married over a plaque in my mother's memory. A place…where I thought I would grow old…But it is also the place that marks the beginning of the end of our family.”

Shiloh and the other children have had to go through a lot to remove Brad Pitt's name from theirs. Here's to hoping some family mending surfaces at some point, and maybe they can get along again.