Goodfellas is now considered one of the best movies ever made, but it wasn’t always like that, as audiences didn’t react well to test screenings, and so the movie went through some changes before its release. Martin Scorsese has become one of the most popular and beloved filmmakers in the industry thanks to the variety of genres he has explored in his movies. However, he’s best known for his gangster movies, and the one often regarded as his best is Goodfellas.

Based on the book Wiseguy by Nicholas Pileggi, Goodfellas chronicles the life of Henry Hill (Ray Liotta), from his days as a teenager running errands for Paul Cicero (Paul Sorvino) and his crew in a neighborhood in Brooklyn, to his full involvement with the Lucchese crime family and his decision to become an FBI informant years later. Goodfellas was very well-received by critics and won various awards, most notably the Academy Award for Best Supporting Actor for Joe Pesci, who played Tommy DeVito, but the movie wasn’t always a success.

Related: Goodfellas: Every Mafia Rule & Code That Henry Hill Broke

By the time Goodfellas was released, Scorsese had already shown what his filmmaking style was all about, with movies like Mean Streets, Taxi Driver, and Raging Bull, but the audience wasn’t entirely ready yet for a movie like Goodfellas. The movie is graphic in its depiction of violence, something that Scorsese wanted to keep as realistic as possible, but the first people who got to watch Goodfellas weren’t on board with it. This was also the first time the studio obligated Scorsese to preview a movie, and it wasn’t a nice experience as viewers weren’t comfortable with what they were watching.

Speaking to GQ in 2010, executive producer Barbara De Fina shared a bit of the experience of test screening Goodfellas and the audience’s reaction to it. De Fina explained that previews were “scary” as by the time Spider gets killed, viewers would get angry. She added that the audience didn’t like the part where Henry is on drugs as it “would agitate them”, with Scorsese explaining in a separate conversation that that was the whole point of the scene. The audience was so uncomfortable and angry at the crew behind Goodfellas that De Fina recalls they “wound up hiding in a bowling alley”, and that one guy wrote a very rude note on the comment card.

All those comments and reactions ended up impacting the final cut of Goodfellas, as Scorsese had to remove 10 frames of blood to ensure an R rating, changed the scene where Billy Batts is stabbed (from seven stabs on-screen to four and the rest off-screen, focusing on Jimmy Conway’s reaction instead), and cut the sequence of Henry’s drug problems to make it faster and with more jump cuts, and with that the purpose of the scene remained intact but was also toned down. It all worked out for the best as Goodfellas is now among the greatest movies ever made, and it will be up to viewers’ imagination to decide if it would have been better with those extra stabs and frames of blood or if those changes were necessary.

Next: Goodfellas: How Real-Life Gangsters Reacted To The Movie