In The Secret Life of Walter Mitty, Ben Stiller plays a mild-mannered desk lackey who finds himself on a quest around the world. At one point, the adventure sends him careening down a mountain on a skateboard. Stiller (who also directed the film) says yes, he took on the stunt himself.

Stiller relied on a lone safety wire, in case the whole operation went south. “It happened a couple of times,” he tells Kurt Andersen. “I was pulled up off the skateboard and dangling like a marionette going 40 miles an hour.”

He’s no Tony Hawk, but this wasn’t Stiller’s first time on a skateboard. “I grew up in New York and skateboarded as a kid,” he says. “I can’t really do tricks or anything, but I’ve always been comfortable on a board and I still love them.”

Listen to a bit of their conversation above — we’ll broadcast more in January. The Secret Life of Walter Mitty opens on Christmas Day.