The Fault in Our Stars actor Ansel Elgort revealed on his Twitter page today that Willem Dafoe has joined the cast as Dr. Peter Van Houten.

The story follows Hazel Grace Lancaster (Shailene Woodley), a teenager who joins a support group after being diagnosed with cancer. Hazel begins to fall for another cancer-stricken teenager Augustus (Ansel Elgort) from her group. Sam Trammell and Laura Dern are playing Hazel's father and mother, with Nat Wolff playing Isaac, Augustus' best friend.

Josh Boone is directing, with Temple Hill's Marty Bowen and Wyck Godfrey producing. Shooting is already under way in Pittsburgh.

Willem Dafoe will next be seen in Tomorrow You're Gone, Odd Thomas, Out of the Furnace and Nymphomaniac.