Eli Roth has said it's vital to "stick up for yourself" in Hollywood.
The director, best known for horror flicks Hostel and Cabin Fever, said getting credit for his work was vitally important.
He told Variety: "Every single time I see a cut of any of my trailers, if my name's not in it I throw a fit, I go crazy - I tell them 'Go f*** yourselves!' and they immediately say 'We're sorry! We didn't know!'."
"You have to do that. If you don't stick up for yourself, nobody else will."
Eli also revealed first impressions mattered when he was trying to get backing for his latest movie Aftershock, which he wrote, produced and stars in.
After just three weeks of filming, the star produced a trailer so he could work out how to sell the film.
"I showed that (trailer) to Bob Weinstein, and he bought the movie off the trailer," Eli said.