'It: Chapter 2' casts Isaiah Mustafa

Isaiah Mustafa has been roped in to play the adult version of Mike Hanlon in "It: Chapter 2".

The 44-year-old actor took to Instagram to reveal the news. He will replace Chosen Jacobs in the follow-up to the 2017 film.

"So excited to join the Losers Club and @itmovieofficial! Big thanks to my @freeform family, @newlinecinema and @wbpictures for getting the stars to align. Major love to @andy_muschietti, Rich Delia Casting and @lissymaren," Mustafa wrote alongside a screenshot of an article by Variety confirming his casting.

Jacobs also took to Instagram to make the announcement.

"You're one of us now @isaiahmustafa. #ITMovie," he wrote alongside Mustafa's photograph.

Mustafa joins Jessica Chastain, James McAvoy, Bill Hader, and Jay Ryan, who are set to play Beverly, Bill, Richie, and Ben, respectively, in the sequel.

Bill Skarsgard will return as Pennywise the Clown, with Andy Bean as Stanley Uris and James Ransone as Eddie Kaspbrak.

Andy Muschietti, who directed "It," is returning for the second installment. Producers Barbara Muschietti, Roy Lee, Dan Lin, Seth Grahame-Smith, and David Katzenberg are believed to be back as well.

Gary Dauberman is penning the script.

The sequel will bow on September 6 next year, with production expected to start this summer.

Based on Stephen King's 1986 novel of the same name, "It" focuses on a group of friends in a fictional Maine community that battles the small towns demon as kids, and then again as adults. The first movie centres on the children, while the upcoming film will follow them into adulthood.