Because Chaves views The Conjuring Universe films as love letters to horror classics, he also included a reference to one of the first horror franchises he ever saw. "The fourth [A Nightmare on Elm Street] was the first one I saw, which was the one with the waterbed. Which, yes, this is a shameless reference to that movie," he shared in an interview with Bloody Disgusting. "Ironically, my assistant director [Jeffrey Wetzel] worked on that movie, so I had him tell me all the waterbed secrets. I needed to know how they did it." It's revealed that David Glatzel didn't knowingly invite the demon to possess him. Instead, he interacts with a waterbed above a cursed totem in a scene reminiscent of A Nightmare on Elm Street 4: The Dream Master.