Lea Thompson was hesitant to work with Michael J. Fox after her friend Eric Stoltz was fired from Back to the Future.

Dozens of major names circled the role of Marty McFly, but only one man could get it…Well, make that two. While Eric Stoltz was originally cast in the Back to the Future role, director Robert Zemeckis would ultimately decide he wasn’t right for the part, canning him less than two months into filming. With that, Michael J. Fox would step in and help make modern movie history. But for Lea Thompson, it took quite a while to get used to her new co-star.

Appearing on the Still Here Hollywood podcast (via EW), Lea Thompson said she was initially distant to Fox, thinking his TV work on Family Ties wasn’t up to snuff with her big screen successes…“I remember specifically being really snooty because there was a big division between movie stars and TV stars at that point. I remember being like, ‘He’s just a TV star and I’m a movie star — I was in Jaws 3D.’ So I think it took me a while to warm up to him.”

Much of this came from Lea Thompson already having a working relationship with Eric Stoltz, having co-starred in the previous year’s Cameron Crowe-penned The Wild Life. The two would work together again, however, on 1987’s Some Kind of Wonderful. Eventually, Lea Thompson and Michael J. Fox did hit it off, creating a chemistry that feels both genuine and, yes, creepy…

Working with both Eric Stoltz and Michael J. Fox on Back to the Future gave Lea Thompson a unique opportunity to see how two completely different actors would handle a given scene. As she recalled, “He was so funny and fun to act with…[I’d] done some scenes with Eric already, and then I did them with Michael, so I could see how they were completely different scenes.” Obviously Fox ended up being the perfect choice for Marty McFly, but if you are curious about Stoltz’s performance, some of his discarded scenes can be found online.

What do you think the chemistry between Lea Thompson and Michael J. Fox brings to Back to the Future? Would the movie have been as much of a hit with Eric Stoltz as Marty McFly? Hop in that DeLorean and let us know below!