Bob Dylan has admitted to using an autopen to sign his new book, despite it being promoted as “hand-signed.”

Dylan fans who splashed out $599 for the limited-edition book, called The Philosophy of Modern Song and published by Simon & Schuster, started to become suspicious after realizing the signatures in the books weren’t just similar, but identical.

It soon became apparent that the 81-year-old music legend had used an autopen, a contraption that can replicate a person’s signature, saving them many hours of work in the process while also preventing potential hand cramps.

Dylan recently admitted to using an autopen and posted an apology on Facebook that included an interesting explanation as to why he ended up using a machine to sign the 900 books instead of his own hand.

“I’ve hand-signed each and every art print over the years, and there’s never been a problem,” Dylan said. “However, in 2019 I had a bad case of vertigo and it continued into the pandemic years.”

The creator of hits such as Blowin’ in the Wind and Like a Rolling Stone continued: “It takes a crew of five working in close quarters with me to help enable these signing sessions, and we could not find a safe and workable way to complete what I needed to do while the virus was raging. So, during the pandemic, it was impossible to sign anything and the vertigo didn’t help. With contractual deadlines looming, the idea of using an autopen was suggested to me, along with the assurance that this kind of thing is done ‘all the time’ in the art and literary worlds. Using a machine was an error in judgment and I want to rectify it immediately. I’m working with Simon & Schuster and my gallery partners to do just that.”

Simon & Schuster said in a tweet it was sorry for what had happened, but added: “As it turns out, the limited-edition books do contain Bob’s original signature, but in a penned replica form. We are addressing this information by providing each purchaser with an immediate refund.”

The autopen isn’t a new device. The first version of the apparatus was patented in the U.S. more than 200 years ago, with celebrities, politicians, and other prominent figures among those making use of it. American presidents including Thomas Jefferson and Lyndon B. Johnson are known to have used it while in office, while Barack Obama became the first to enact legislation with an autopen-generated signature, in 2011.