Mariah Carey's 'All I Want for Christmas Is You' is a holiday staple; it's impossible to enter any Target or Macy's in December without hearing it at least once. But this Christmas, Carey's classic tune will get the Justin Bieber treatment -- transforming it from a worldwide hit to something unfathomably huge.

The Biebs, who turns 18 in March, sat down with Capital's Rich Clarke to dish on working with Miss Mimi. According to Bieber, Mariah is "really cool" and "down to earth," and he thinks his fans are really going to dig their joint version of 'All I Want for Christmas Is You.'

"The new version's really cool," the 'Baby' singer spilled. "It starts out with a Disney kind of opening and then she starts the song and I come in during the second verse."

While that little tease is almost too much to handle, Beliebers won't have to wait much longer to get their paws on the Biebs' latest release. His debut holiday album, 'Under the Mistletoe' (which also features Usher and Boyz II Men), will hit the shelves on Nov. 1.