Image source, Getty Images

Ariana Grande will play the witch Galinda in the film adaptation of Wicked.

The musical, which is about the witches from The Wizard of Oz, will also star British actor Cynthia Erivo as Elphaba, the Wicked Witch of the West.

A movie version has been in the works for years.

Earlier this year, it was announced that Jon M Chu, whose previous films include Crazy Rich Asians and In The Heights, will direct.

View this post on Instagram

A post shared by Ariana Grande (@arianagrande)

Ariana Grande, Cynthia Erivo and Jon M Chu all announced the casting on Instagram, posting screenshots of a group call between them.

A note from Ariana to Cynthia said: "Dear Cynthia, honored doesn't even begin to cover it. I cannot wait to hug you. See you in Oz."

Cynthia also sent flowers the other way, with a note that said: "Congratulations Miss A, the part was made for you, I look forward to sharing this musical journey with you. Love, Cynthia."

Jon M Chu posted: "Wait until you see what they bring!! It is other worldly. Ahhhhh!!!"

Image source, Getty ImagesImage caption, Cynthia Erivo and Jon M Chu posted screenshots of their group call with Ariana Grande

Wicked began on stage in 2003, based on a 1995 novel which tells the story of the Wizard of Oz from the perspective of the witches.

It went on to become one of the most successful musicals of all time.

It's only the third show to have made over $1bn (£742m), along with The Phantom of the Opera and The Lion King.

Ariana Grande got her break as a teenager on Broadway, playing a cheerleader in the musical 13.

She's also sung a Wicked song live before, performing The Wizard and I at the musical's 15th anniversary show in 2018.

Figure caption, Warning: Third party content may contain adverts

Grammy, Emmy and Tony award winner Cynthia Erivo is a well-known stage actor, performing in The Colour Purple and Sister Act.

She's appeared in films including Bad Times at the El Royale and Widows.

In 2019, she was nominated for two Oscars, for her portrayal of the political activist Harriet Tubman in the film Harriet, and for the song Stand Up, which was part of the film's soundtrack.

The Wicked film doesn't have a release date yet, but it's been reported that it will be co-written by original writers Stephen Schwartz and Winnie Holzman.

Image source, Getty ImagesImage caption, Idina Menzel and Kristin Chenoweth played the original Elphaba and Galinda in Wicked

Follow Newsbeat on Instagram, Facebook, Twitter and YouTube.

Listen to Newsbeat live at 12:45 and 17:45 weekdays – or listen back here.