If you've been imagining Martin Scorsese's upcoming Robert De Niro film The Irishman as a quasi-sequel to Goodfellas then his longtime collaborator has some news for you: it really, really isn't.

Thelma Schoonmaker, Scorsese's editor for more than 50 years on films including Raging Bull, Goodfellas, The Wolf of Wall Street, Gangs of New York and The Departed, was at pains to distance the two and, to be fair, if anyone knows the difference then she certainly does.

"The Irishman is not Goodfellas," Schoonmaker told Yahoo Movies. "And that's what they think it’s going to be. It's not. It is not Goodfellas. It's completely different. It's wonderful. They're going to love it. But please don’t think it's gonna be Goodfellas, because it isn't."

Aside from the reunion between Scorsese and De Niro, the big intrigue around The Irishman comes from the CGI which will magically return De Niro and his co-stars to their youth.

"We're youthifying the actors in the first half of the movie. And then the second half of the movie they play their own age. So that's a big risk."

But, Schoonmaker says, the technical achievement is so good that you stop noticing it. "Nobody minds," Schoonmaker said. "Nobody minds watching them play young, because they’re gripped."