Will Ferrell agreed to cameo in A Very Jonas Christmas Movie as part of 'Old Hollywood trade'

Will Ferrell agreed to make a cameo in A Very Jonas Christmas Movie as part of an "Old Hollywood trade-off".

In the new festive film, Jonas Brothers stars Kevin, Joe, and Nick Jonas face a series of escalating obstacles as they struggle to make it from London to New York in time to spend Christmas with their families.

Will makes a surprise cameo with his wife and sons in the opening scene of the film, and during a recent interview for ABC News, the siblings recalled how the comedy icon instantly agreed to appear in the project as a Jonas Brothers super fan.

"It was a trade," said Kevin, while Joe insisted, "An Old Hollywood trade-off."

Nick went on to explain that he approached the Anchorman star after he made a cameo in his comedy, You're Cordially Invited.

"I did a cameo in his movie with Reese Witherspoon, a very small part. Anyway, I texted him, I was like, 'Hey, we're doing this Christmas movie, and if there's any chance you could do it? And he said, 'Yes.' Which blew our minds," the 33-year-old smiled.

A Very Jonas Christmas Movie includes appearances from Chloe Bennet, Billie Lourd, Laverne Cox, KJ Apa, Kenny G, Randall Park, and Jesse Tyler Ferguson.

There are also cameos from Nick's wife Priyanka Chopra and their daughter Malti, as well as Kevin's wife Danielle Jonas and their daughters Alena and Valentina.

"I was thrilled she was down to be a part of it. She was a big get for us for this film, big name. It's great to include some of those real-life elements and having her be a part of that was special for me," Nick gushed about his wife, while Kevin added: "My girls were very excited to get into the acting game. They were like, 'Come on Disney, put us in!'"

A Very Jonas Christmas Movie is now showing on Disney+ and Hulu.