Looks like newly engaged Scarlett Johansson can cross shopping for a bridal gown off her to-do list.

“I’m definitely doing her wedding dress,” says fashion’s Stella McCartney, People.com reports. There’s only one hitch before Johansson, 23, gets hitched to fiancé Ryan Reynolds, according to McCartney: “She doesn’t know it yet.”

As for what McCartney has in mind “You know, some kind of dodgy, black thing,” McCartney, tongue firmly planted in cheek, joked. “Latex! Latex for Scarlett!"