John Green wrote one of the top bestsellers books in publishing history, and now he’s added another distinction to his résumé.

The author has been recognized with a Guinness World Record for the most tip-in sheets signed by an author in their lifetime, having given his John Hancock to a staggering 875,557 pages. Tip-in sheets are printed separately from a book and later attached to it; publishers frequently use them to include authors’ autographs.

Green has sold more than 50 million copies of his books, with his 2012 young adult novel, The Fault in Our Stars, responsible for nearly half of that number. His other books, including Looking for Alaska, Paper Towns, Turtles All the Way Down, and Everything Is Tuberculosis have all been bestsellers.

Green’s latest novel, Hollywood, Ending—his first for adults—was published Tuesday by Dutton. In a starred review, a critic for Kirkus called the book “a classic Green portrait of young love…but here the fault is in our social media.” He launched the book on Tuesday at an event in Brooklyn, where Guinness World Records adjudicator Ryan Masserano presented him with the award.

“This is a special accomplishment that I am proud to have achieved,” Green said. “Tonight, I get to go to sleep as a Guinness World Records title holder!”

It is, of course, an impressive achievement. But if you happen to see Green on the street, maybe don’t give him a vigorous handshake.

Michael Schaub is a contributing writer.