The actor, who turned 50 on December 18 reportedly did not do anything special for his milestone birthday, reported Ace Showbiz.
"He's not doing anything for it and he said he doesn't want any surprises. He really doesn't want to talk about his birthday much," the source said.
Pitt apparently celebrated his birthday with partner Angelina Jolie and their children Maddox, Pax, Zahara, Shiloh, Vivienne and Knox in Australia.