Backrooms looks like it could be one of the breakout movies of the summer. It’s getting very solid reviews from critics (it’s at 80 percent on Rotten Tomatoes as of this writing) and is tracking to open somewhere in the neighborhood of $30-$50 million.

That would be a great first weekend for any indie horror movie, but for something directed by a 20-year-old filmmaker — Kane Parsons, who created “The Backrooms” as a series of shorts on YouTube, then adapted his work to the big screen for A24 — it’s kind of unheard of.

That might be why there are some people (people, anonymous trolls, same difference) who are whispering that Parsons didn’t actually direct the movie. They point to the number of famous filmmakers who are involved with Backrooms as producers — including James Wan, Osgood Perkins, and Shawn Levy — as proof that one or all of them secretly directed Backrooms on Parsons’ behalf. (Think a modern version of the persistent urban legend that producer Steven Spielberg ghost directed Poltergeist rather than the credited filmmaker, Tobe Hooper.) According to this theory, that’s the only reason the film is good; one of these other, more experienced guys made it.

But one of the stars of Backrooms says these theories are flat-out incorrect. Mark Duplass, who’s a pretty good director in his own right, responded to these theories on his Instagram account, and completely dismissed all of them them.

“So a lot of takes are going around right now about whether Kane Parsons at the tender age of 19 actually directed Backrooms, or whether it was ghost-directed by one of his more experienced producers,” he said.

“I was there,” Duplass added. “I suspect one of the reasons I was hired is because I mentor a lot of young filmmakers and they may have thought it would be good to have someone there who’s sensitive to that. And I was prepared to help out. And what what happened was he didn’t need any of us.”

READ MORE: ScreenCrush’s Full Review of Backrooms

Duplass also said of Parsons “He was intensely prepared. He spent the last five years of his life building out one of the most detailed mythologies that I’ve ever been a part of, worked incredibly closely with his crew, particularly his DP, and was very sensitive and calm and smart in dealing with actors. So for those of you who have all these thoughts, were you there?”

So there you have it. Backrooms wasn’t directed by a guy who’s only 20 years old. It was directed by a 19 year old. The film opens in theaters this weekend.