The billionaire co-founder of PayPal (PYPL) and CEO of Tesla (TSLA) and SpaceX has often aired his misgivings about the technological advancement. He’s even backed a non-profit research organization, Open AI, that aims to ensure the tech is developed ethically and safely.

Now, in a video teaser shared exclusively with Fortune, Musk clarifies what he deems is the “biggest risk” that AI poses to humanity. The clip is a short segment from Lo and Behold, the latest film by German filmmaker Werner Herzog, due out this week. In it, Musk conjures a dystopian future usurped by profit-seeking AI warmongers.

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“I think that the biggest risk is not that the AI will develop a will of its own,” Musk says, clarifying his unease, “but rather that it will follow the will of people that establish its utility function.”

“If it is not well thought out—even if its intent is benign—it could have quite a bad outcome,” he continues, going on to provide a hypothetical doomsday scenario in which robo-investors incite war. “If you were a hedge fund or private equity fund and you said, ‘Well, all I want my AI to do is maximize the value of my portfolio,’ then the AI could decide, well, the best way to do that is to short consumer stocks, go long defense stocks, and start a war.”

“That would obviously be quite bad,” Musk says, lowering his eyes, dispassionately.

See also: “Elon Musk’s Artificial Intelligence Project Just Got a Free Supercomputer”

The scene cuts to shadowy room in which a statue of a Cylon, a genocidal cybernetic race in the apocalyptic sci-fi television show Battlestar Galactica, looms. Herzog’s distinctive drawl remarks:”Such an attack would be much more prosaic than an invasion of these aliens in the SpaceX reception area.”

In past interviews, Musk has hinted that a certain company’s approach to AI worries him. With a wink and a nod, you might recognize Google, rather than Facebook (FB), as his prime motivator for advocating caution, as The Verge has noted.

Meanwhile, Eric Schmidt, chairman of Google’s parent company Alphabet (GOOG) and an advisor to the Pentagon, has dismissed people’s fears about the tech and embraced it more openly. Schmidt has said that he believes AI has great defensive potential, though he has concerns about it falling into the hands of dictators and authoritarian regimes.

Meanwhile, other interested parties have told people that AI will do more good than harm. A research scientist at IBM (IBM) told Fortune’s sister magazine Time earlier this year that he believes Musk and Cambridge physicist Stephen Hawking’s fears about AI are “overblown.”

Herzog’s homage to the Internet, sponsored by the IT networking firm Netscout, comes out Aug. 19th.