Credit: Ton Koene

The film version of John Green’s best-selling YA novel Paper Towns comes out later this summer, and the author has been revisiting the 2008 book in recent months. But when a fan called Green out for using the slur “retarded” in the book, Green apologized on Twitter and said he regrets printing the word.

The word appears in Paper Townsduring a scene in which the main character Quentin Jacobsen, who will be played by Nat Wolff, and his neighbor Margo Roth Spiegelman (Cara Delevingne) go on an all-night adventure, binding them together. One character says, “Sometimes he’s so retarded that he becomes kind of brilliant.”

Green also noted that the word won’t be heard in the film adaptation.

Check out the trailer for Paper Towns below: