John Candy was offered the role of Louis Tully. Candy told Reitman he did not understand the character, and suggested portraying Tully with a German accent and multiple German Shepherds; the filmmakers felt there were already enough dogs in the film. They and Candy passed on the casting. Reitman was already aware of Rick Moranis from their work together in Toronto and sent him the script. He accepted the role an hour later. Moranis developed many aspects of his character, including making him an accountant, and ad-libbed the lengthy speech at Tully's party. Sandra Bernhard turned down the role of Ghostbusters' secretary Janine Melnitz, which went to Annie Potts. As she arrived for her first day of filming, Reitman rushed Potts into the current scene. She quickly changed out of her street clothes and borrowed a pair of glasses worn by the set dresser. Her character ended up wearing the glasses throughout the film.