Lots of kids in Perth, Australia, slept in their parents’ beds on Tuesday night.

That’s after a local cinema scared parents and their young brood witless after accidentally rolling the trailer for R-rated horror flick “Hereditary” at a viewing for “Peter Rabbit.”

One adult moviegoer, identified solely by her first name, Jane, tells Perth’s WAtoday that “at least 40 children” were present in the theater Tuesday afternoon, which was a national holiday.

Kids and parents shrieked at the trailer’s horrific scenes, which included a young boy bloodily cracking his head on a desk, a coffined corpse and self-immolation.

“Parents were yelling at the projectionist to stop, covering their kids’ eyes and ears,” Jane tells WAToday. Some parents tried to find help, while other families simply left the room.

The mayhem finally ceased when a walkie-talkie-armed employee shut off the display. The theater apologized, attendees received a free movie ticket as consolation and “Peter Rabbit” rolled on.

“Hereditary,” starring Toni Colette, has already been dubbed this generation’s “The Exorcist.”