Emma Watson has joined the cast of 'Little Women'.

The 'Harry Potter' actress will star alongside the likes of Meryl Streep, Laura Dern and Saoirse Ronan in Greta Gerwig's adaptation of Louisa May Alcott's classic novel, replacing Emma Stone, who was unable to commit to the project because of her promotional obligations to 'The Favourite'.

The movie - which is also being written by Greta - tells the story of four sisters as they transition from childhood to womanhood.

According to Variety, roles in the film are still being worked out so it is unknown which of the March sisters will be played by Watson.