As Robert Downey Jr. hit the big six-oh, his son Indio marked the occasion with a rare and sweet throwback.

A day after the Iron Man star’s birthday on April 4, the 31-year-old musician took to Instagram to celebrate his dad’s milestone birthday with a mix of past and present.

The post featured a recent snap of the two at an event, along with a sweet black-and-white photo of young Indio kissing Robert on the cheek. The actor wore a T-shirt that read “Brat” as little Indio pressed his tiny hand to his face.

“It’s the big 6-0 for the legend @robertdowneyjr! happy birthday dad… you’re the best,” Indio wrote.

Robert shares Indio with ex Deborah Falconer and has two younger kids — Exton, 13, and Avri, 10 — with wife Susan Downey.

Speaking to People magazine earlier this year, Indio revealed how much his dad shaped his creative path. “My dad actually really inspired me to play music when I was young,” he said, adding, “He sings, and he has an album as well that I listen to a lot.”

Meanwhile, Downey Jr. is trading the Iron Man suit for something darker. The actor is set to return to the MCU — this time as the villainous Doctor Doom in Avengers: Doomsday.