Mystery and thriller novelist Anthony Horowitz told the Independent that he uses ChatGPT to assist in his writing.

Horowitz is known for his popular Alex Rider series of young-adult books, as well as novels for adults including The Word Is Murder, The Twist of a Knife, and A Deadly Episode, published last month. He said that he uses the artificial intelligence chatbot “all the time.”

“I feel nervous about it, because, is it cheating?” he told the U.K. newspaper in an interview published Tuesday. “I feel a bit like it’s cheating in a school exam.”

He added that he believes it’s important to fact-check the output he receives from the chatbot.

“It’s useful to have immediate knowledge, but not unrestrained,” he said. “You’ve always got to judge what you’re being told, and also look for a second source. In the old days, I’d go to a library, I’d look up stuff in books. What’s the difference between using AI and going straight to the point?"

He also noted the limitations of artificial intelligence, recounting a time he used ChatGPT to get a description of how a potato is shaped, and he was given the word ellipsoid.

“This is when you drop the artificial intelligence and use your own intelligence,” he said. “Readers hearing that the potato on her plate was ‘ellipsoid’ are going to say, ‘What the hell is this guy talking about?’”

Artificial intelligence has been a contentious subject in the literary world. Last year, dozens of authors signed an open letter to the Big Five publishers, asking that they promise never to release books “created by machines.” And earlier this year, Hachette canceled a horror novel it had planned to publish—Mia Ballard’s Shy Girl—after it was alleged that the book was written using AI.

Michael Schaub is a contributing writer.