Marty McFly is returning to his rock-star roots.

On Saturday, Back to the Future star Michael J. Fox made a surprise appearance at the 2024 Glastonbury Festival during Coldplay’s headlining set.

The band’s frontman, Chris Martin, was freestyling lyrics to point out famous figures in the crowd and, after calling attention to the festival's co-founder, Michael Eavis, he turned his attention to Fox, who was waiting backstage.

"Here's another legendary Michael,” Martin sang, strumming his guitar. “One who just totally rocks. With his Chuck Berry riff and the way he punched Biff, ladies and gentleman, please welcome Michael J. Fox."

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Fox, who was diagnosed with Parkinson’s disease in 1991, was in a wheelchair when he joined the band on stage with a guitar, jamming along with them for the final two songs of their set,  “Humankind” and “Fix You.” During the latter song, Martin united with Fox center stage as he strummed the buildup to its dramatic bridge.

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Following the performance, Martin thanked the cheering audience before giving Fox a special shout-out. "Especially, thank you," he said. "The main reason why we’re in a band is because of watching Back to the Future. So thank you to our hero forever, and one of the most amazing people around, Mr. Michael J. Fox.”

This wasn’t the first time Fox hit the stage to support the band. He collaborated with Coldplay at the MetLife Stadium in New Jersey in July 2016 for a performance of “Johnny B. Goode,” the Chuck Berry song featured in Back to the Future.

Martin opened up about that special moment during a 2022 appearance on The Kelly Clarkson Show, telling the Grammy-winning host that it was especially meaningful because seeing Fox's character Marty McFly sing the song in the 1985 sci-fi classic was life-changing.

“That was really wonderful, “ he said of sharing the stage with Fox, before adding, "That's what made me want to be in a band, you know? That scene."

Coldplay formed at University College London in 1997. Their current lineup includes lead singer Martin, guitarist Jonny Buckland, bassist Guy Berryman, and drummer Will Champion.

Watch Fox perform with the group at Glastonbury in the video above.