Watch Mariah Carey and Michael Bublé singing "All I Want For Christmas Is You" live

Mariah Carey made an appearance on "Michael Bublé's 3rd Annual Christmas Special."

The singers performed Carey’s classic Christmas song, "All I Want For Christmas Is You," which was recorded for her fourth studio album “Merry Christmas.” Carey co-wrote and co-produced the track in collaboration with Walter Afanasieff.

Check out the duet below: