Elon Musk may be pushing to bring cars into the modern era with Tesla Motors, but as it turns out, the billionaire CEO is a bit afraid of technology. Indeed, according to a recent report from Market Watch, Musk recently spoke about about the dangers of artificial intelligence, even going as far as to call AI “our biggest existential threat.”

Musk’s comments about artificial intelligence were made on Friday night, during a talk that the CEO was giving at MIT. He said that, by trying to constantly improve AI, “we are summoning the demon.”

“In all those stories where there’s the guy with the pentagram and the holy water, it’s like, he’s sure he can control the demon,” Musk said. But as the CEO noted, controlling “the demon” is never as easy as it seems. With artificial intelligence, Musk seems afraid that humanity would lose control of the machines and face the consequences.

So has Musk been watching too many movies, or are his points valid? Have marathon hours of The Matrix and the Terminator films warped his judgment, or is AI destined to destroy us when we finally succeed in creating machines with free will and decision-making skills?

At this point, it would be tough for anyone to disassociate the coming reality from the countless science fiction cautionary tales we have seen over the years. However, for his part, Musk is not alone in fearing the future of artificial intelligence. Stephen Hawking has also spoken out against the technology, stating that it could be the ruin of humanity.

As the Market Watch article noted, though, not everyone buys into Musk’s biblical doom scenario. Marc Andreesen, a venture capitalist and entrepreneur with technology leanings, slammed Musk as someone who “doesn’t know what he’s talking about,” and joking that there will be nothing to worry about until “iPhone autocorrect starts to work reliably.”

Musk’s response? “Famous last words,” the CEO quipped about Andreesen’s words.