Ed Sheeran will guest star on next season of 'Game of Thrones' and it's all because of Maisie Williams

Game of Thrones has nabbed its biggest guest star yet.

Ed Sheeran will appear in an episode of Season 7, according to showrunners David Benioff and Dan Weiss, who announced the news at their South By Southwest panel on Sunday.

The Q&A was moderated by Thrones stars Maisie Williams (Arya Stark) and Sophie Turner (Sansa Stark), and Benioff noted that Williams was the reason they wanted the "Shape of You" singer for a guest role in the first place.

"We knew that Maisie was a big fan of Ed Sheeran, so for years we tried to get Ed Sheeran on the show so we could surprise Maisie, and this year we finally did it," he revealed.

"I'm still waiting on Bieber," Turner quipped, to which the showrunners promised in deadpan unison: "Season 9."

The show has a habit of tapping musicians for cameos. Previous guest stars have included Mastodon, one of Weiss' favorite bands; Gary Lightbody from Snow Patrol; Will Champion from Coldplay; and Sigur Ros.

Benioff and Weiss also confirmed that Season 8 will be six episodes long during the SXSW panel, meaning that we only have a total of 13 episodes left before Game of Thrones leaves our screens forever -- say it ain't so!

Game of Thrones Season 7 will premiere its seven episode run on July 16, with production on the final season set to begin later this year.