Brad Pitt has been entertaining cinemagoers for over 30 years.

Yesterday, the screen legend celebrated his birthday, with his sons taking to social media to mark the occasion. Fifteen-year-old Pax Jolie-Pitt shared a sweet throwback photo of his dad as a child to mark the actor's 55th birthday.

"Happy Birthday to this stud. Love you so much! Can't wait to see you later," he wrote. His older brother Maddox, 17, also paid tribute to the Hollywood actor on social media as he wished a happy birthday to "the coolest dad."

Pax was adopted by Angelina in March 2007 from an orphanage in Ho Chi Minh City, Vietnam, two years after she met Brad on the film set of Mr. & Mrs. Smith.

But it wasn't just Pitt's sons who took to social media to wish Brad Pitt a joyous birthday. Pitt's co-star in the movie The Mexican, Julia Roberts, also sent birthday wishes on Tuesday. The 51-year-old Pretty Woman star took to Instagram to share a photo of the two from their 2001 film.

"Happy Birthday to one of the all time GREATS,'' the Oscar-winner captioned the photo adding the word "LOVE."

The birthday tributes come just one week after it was alleged that Angelina told Pax his father "never wanted to adopt him," according to an Us Weekly source. Jolie and Pitt have been locked in a bitter custody dispute since announcing their split in September 2016. The insider told the publication that Jolie's words "harmed the relationship" between Brad and Pax. The source claimed that Brad was not against adopting the then 3-year-old Pax, but worried about the timing. Pax could hardly speak English and was adopted less than a year after they welcomed their daughter Shiloh.

Angelina allegedly told him at the time, "Pax needs me more than Shiloh."

Forty-three-year-old Jolie also reportedly told Pax that Brad "was angry" she had proceeded with the adoption. Late last month, lawyers revealed that the A-List couple had finally come to a custody agreement regarding their six children: Maddox, Pax, Zahara, Shiloh, and twins Vivienne and Knox. Angelina reportedly wanted full custody but settled to share physical and legal custody to avoid dragging the kids into a trial.

The source also told Us Weekly, both Jolie and Pitt's parenting skills have been criticized by social workers.

The insider claims Brad has been able to seek help for his "anger and psychological issues," however one social worker "felt he had trouble accepting personal responsibility and often blames others for his actions."

It was also alleged that Angelina "indulges the kids all the time and lives in an unstable living environment."