The films of Steven Spielberg were a huge influence on the book Ready Player One, but now that Spielberg himself is directing the movie adaptation, he’s going to have to change the source material just a bit.

The book by Ernest Cline features several references to movies Spielberg directed or produced, like Raiders of the Lost Ark, Gremlins and Back to the Future, but it would be a bit strange and self-congratulatory for a Spielberg movie to geek out over Spielberg movies. Therefore, the director says he'll be cutting out all of these references from the movie.

“The movie won’t have any of my films in it," Spielberg told EW. “I’m not putting myself in this movie.”

He says the movie will still feature plenty of '80s nostalgia, as well as references to other films, but he just thought it was too self-referential to constantly bring up his own films.

That decision definitely makes sense, although it means the adaptation will need some tweaks in the story. For example, in the book the lead character travels around in a custom DeLorean from Back to the Future, but since Spielberg produced that movie, this will have to be changed to something else or left out entirely.

Ready Player One takes place in the year 2044, where everyone logs on to a virtual world called the OASIS in order to escape from reality. Spielberg said he was interested in the story because he found it to be an interesting prediction of where society is headed in the next few years, where people spend more and more time in digital environments over real ones.

“This movie is going to show why it’s interesting not living in the real world but what we’re missing by not,” he told USA Today. “It’s a cautionary tale but it’s also a big rockin’ adventure movie, too.”

Ready Player One will hit theaters on Dec. 15, 2017.