Selma Blair has been cast in the 'Heathers' reboot.

The 45-year-old actress will portray the stepmother of Brendan Scanlan's Heath Duke in the upcoming TV adaptation, which is based on the 1988 classic teen movie, which starred Winona Ryder and Christian Slater.

Selma announced her casting by sharing a photo of herself on Instagram and referencing a classic line from the film.

She wrote: ''Do I look like step Mother Theresa ? @heathers #paramountnetwork2018 (sic)''

Selma's alter ego, Jade, is described as rough-round-the-edges, gold-digging stripper who is biding her time until her 82-year-old husband passes away.

The new take on the cult classic is set in the present day and sees Veronica Sawyer (Grace Victoria Cox) come up against a very different group of Heathers, who were outcasts but have escalated in the ranks of school popularity, including Jasmine Andrews as Heather McNamara and Melanie Field as Heather Chandler.

Newcomer James Scully will take on the role of mysterious outsider J.D., the role originally played by Christian Slater.

Shannen Doherty, who was Heather Duke in the original movie, has a guest role in the new show.

The movie saw Veronica (Winona Ryder) team up with J.D. to take down their school's popular clique, without her realising his plan to kill them was to be taken literally.

The TV reboot will premiere on the Paramount Network in 2018. Leslye Headland has directed the pilot episode, based on a script by Jason Micallef.