This Back to the Future mistake fans keep reminding Michael J. Fox of

“It was just an artistic choice in the props department,” says the actor in his memoir…

It took almost forty years for him to talk about it. In his new book Future BoyMichael J. Fox returns to one of the most famous errors of Back to the future — the one that fans have tirelessly reminded him of since 1985.

The famous scene in question: the 1955 prom, where Marty McFly picks up the guitar to play Earth Angel Then Johnny B. Goodeinspired by Chuck Berry. Problem: the guitar he uses, a Gibson ES-345, was only released in… 1958, three years after the scene supposed to take place.

Michael J. Fox calls this anachronistic blunder “time inconsistency that guitar enthusiasts and music fans Back to the future have continued to rise again and again!” He adds:

“We’re talking about a few thousand Back to the Future fans, scrutinizing every detail of the film and dissecting every oddity of the timeline.”

And about the famous guitar, the actor specifies:

“There was no hidden wink: the film’s art department simply chose the ES-345 because it was reminiscent of the iconic red guitar with which Chuck Berry crossed the stage on his famous duck walk around the world.”

However, purists have never tired of pointing out this anomaly. Some go even further, recalling that Johnny B. Goode was not recorded until 1958. Marty, coming from 1985, could obviously have known the song — but how would the 1955 band have known how to play it?

With humor, Fox puts things into perspective: “Whether it’s a 1955 or 1958 Gibson, these instruments are beautiful. I always loved the E series: big, imposing, but light. Even a little guy like me could make them sing.”

Recently, Gibson launched a worldwide hunt for the now-missing guitar from the film. “Since the release of the film, this guitar has become more famous for what it is not than for what it is. What it is not, it is available”jokes Fox. Fans are invited to help the brand localize it via www.losttothefuture.com — with support from the magical trio Michael J. Fox, Lea Thompson and Christopher Lloyd.