Jeff Koons dons a black wig in Milk to play Art Agnos.

Those paying close attention at screenings of Gus Van Sant’s new film, Milk, out December 5, noticed that the biopic starring Sean Penn as gay San Francisco city supervisor Harvey Milk features an unlikely cameo by Jeff Koons. The artist plays the politician Art Agnos, who would eventually become the city’s mayor in 1988; Milk lost to Agnos when he ran against him in 1976 for the California State Assembly. Koons, who wears his hair jet-black in the film, has a short debate scene with Penn. “I saw him on a morning show,” says Van Sant. “I thought he’d be good [in the role]—he was such a good salesman.”

Koons: Andrew H. Walker/Getty Images