Colin Firth, Julie Walters in 'The Secret Garden'

Colin Firth and Julie Walters have come aboard the cast of "The Secret Garden".

Produced by David Heyman, the project is the film adaptation of the children's classic of the same name, according to The Hollywood Reporter.

Marc Munden is helming the film from a script penned by Jack Thorne.

"The Secret Garden" was first published in 1911 and was authored by Frances Hodgson Burnett. The period setting from the book has been changed, moving from the Edwardian era to 1947, on the eve of Partition in India, and in the aftermath of World War II.

It is set in England and follows Mary Lennox, a prickly and unloved 10-year-old girl, born in India to wealthy British parents who never wanted her. When her parents suddenly die, she is sent back to England to live with her uncle, Archibald Craven.

Firth, 57, will play Craven, while Walters, 68, plays Mrs Medlock, the head housekeeper at Misselthwaite.

Dixie Egerickx, Edan Hayhurst, Amir Wilson and Isis Davis are also part of the cast.

Jane Robertson is co-producing the film with Didier Lupfer, Danny Perkins and Dan MacRae executive producing it for Studiocanal.