Brad Pitt and Angelina Jolie's son injured his leg during a family trip to Thailand.
Twelve-year-old Pax Jolie-Pitt, who was adopted from an orphanage in Ho Chi Minh City in Vietnam in 2007, hurt his right leg, but did not break the limb, a source told People.
It's understood he was jetskiing at the time.
The family, Brad, Angelina and their children, Maddox, 14, Pax, Zahara, 10, Shiloh, 9, and 7-year-old twins Knox and Vivienne, spent the festive break touring Thailand.
They have been spending a great deal of time in Asia recently, where Jolie is shooting First They Killed My Father: A Daughter of Cambodia, about the brutal Khmer Rouge regime.
Meanwhile, it was previously revealed that Angelina has given Maddox his first speaking role in the upcoming Netflix drama.
"[Maddox] has been desperate to get into acting. This is a dream come true for him. He's read the book the film's based on and speaks the language - it's a perfect fit."
The teenager, whom the filmmaker adopted from an orphanage in western Cambodia in 2002, had a non-speaking part in 51-year-old Pitt's film World War Z.
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Angelina has not confirmed his acting role but admitted she hired her son to be an assistant on the set of the film.
She explained: "As Maddox and I prepare the film we will be side by side learning about his country. This is a very important time for him to understand who he is. He is my son but he is also a son of Cambodia.
"This is the time for our family to understand all that that means to him and to us. My desire to tell this story in the most truthful and accurate way possible will be my tribute to the strength and dignity of all Cambodian people."
-Bang! Showbiz