You'll never guess which 'Game of Thrones' cast members are gearing up for 'Carpool Karaoke'

Two Game of Thrones cast members are gearing up for winter by getting their karaoke on.

Real-life BFFs Maisie Williams (who plays Arya Stark) and Sophie Turner (who plays Sansa Stark) on Sunday teased they're filming for Apple's upcoming Carpool Karaoke spin-off.

The duo are at South by Southwest for the Game of Thrones panel on Sunday.

SEE ALSO: 'Carpool Karaoke' will debut on Apple Music

The series, which will be Apple Music's first official show, will feature 16 different hosts (one per episode) paired with musical guests. 

Other guests include John Legend and Alicia Keys; Billy Eichner and Metallica; Ariana Grande and Seth MacFarlane; Blake Shelton and Chelsea Handler; and Will Smith and Corden.

It is set to debut in April.

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