Philip Pullman has spoken out against The Chronicles of Narnia film - saying the books are racist and sexist.
The His Dark Materials author told The Observer newspaper that the stories have a message that is outdated, and that they showed a fear of women.
The author raised concerns that "there was not a trace" of love in the fantasy series of books.
Film-makers Disney said that was Pullman's personal opinion, so they didn't want to respond.
The first film, The Lion, The Witch and The Wardrobe, will be released in cinemas in December.
The Chronicles of Narnia
The Magician's Nephew
The Lion, The Witch and The Wardrobe
The Horse and His Boy
The Voyage of the Dawn Treader
The Silver Chair
The Last Battle
Lots of people have said the books give a Christian message, and that lots of the tale mirrors the story of Christ in the bible.
Pullman is well known for speaking out against religion.
His most famous books, the His Dark Materials trilogy, is about a war against the Church and a quest to overthrow God.