Jim Broadbent will play a starring role in the next Harry Potter film as new potions master Horace Slughorn.
Filming began on The Half-Blood Prince on Monday, and Broadbent revealed to a movie website he's got the part.
He said: "He's a retired teacher who's drawn back out of retirement because he's got some secrets they need in the battle against the Death Eaters."
As Potter fans know, Slughorn plays a crucial role in the story, and helps Harry work out how to battle Voldemort.
Slughorn also has links to the darker side of magic, and used to be the head of Slytherin House when he taught at Hogwarts.
Jim added: "He's quite star struck as a teacher and he's drawn back into the fold because he likes to notch up celebrity students, and he's drawn back by Harry."
It's going to be difficult to avoid Broadbent in big-budget films next year, as he's also starring in the Indiana Jones film too, called the Kingdom of the Crystal Skull.