Zooey Deschanel is sharing some behind-the-scenes secrets from her time on “Elf”.

The actress, 40, who starred as Jovie in the beloved holiday film next to Will Ferrel’s Buddy the Elf, chatted with Entertainment Weekly about the “Baby, It’s Cold Outside” scene, revealing it wasn’t part of the original script, in fact, it was tailored to the star.

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“I remember [director] Jon Favreau telling me that they were catering it to whoever played the part,” Deschanel recalled. “One actress they were looking at was good at skateboarding. But I had a cabaret act at the time and I was performing a lot. They knew that I was a singer, so they put that in to be my special thing that he could discover I was good at.”

But it was Ferrell’s pipes that shocked the “New Girl” alum, “He said he wasn’t a singer, so I wasn’t expecting much… But his dad [Roy Lee Ferrell Jr.] is a great musician. I should’ve known he’d be secretly good!”

“It’s funny because obviously everyone knows it’s not appropriate to walk in the girls’ bathroom when someone’s showering, but he’s so believable as this guileless elf,” Deschanel said of the scene. “It’s weird he’s in there, but you totally buy that his intentions are pure and innocent.”

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Deschanel has had a long relationship with “Baby, It’s Cold Outside”, even recording it later on with her She & Him partner M. Ward.

“I was a little hesitant to do it because I had done it,” she admits. “So I said, ‘How about we flip the script and I’ll sing the male part?’ So that’s how we ended up doing it.”

“Elf” first premiered in 2003.