Brad Pitt was the epitome of cool and commanding as tough-as-nails stuntman Cliff Booth in 2019’s Once Upon a Time in Hollywood.

But when on set, Quentin Tarantino made it clear who was calling the shots.

According to a People interview, co-star Bruce Dern gave at Cannes, the Oscar winners had a tense exchange while working on the blockbuster film.

In the movie, Dern plays blind ranch owner George Spahn. During one scene, Pitt’s Booth wakes up Spahn to check and see if he’s OK. Dern says he improvised a line.

“When Brad Pitt wakes me up in Once Upon a Time in Hollywood, I’m in the bed and I get up and I’m a little groggy and stuff and I just say, ‘I’m not really sure what’s going on,'” Dern said. “I’m looking at him. [Pitt] cut the camera. He cut the camera.” (Meaning, Pitt told the camera crew to stop recording).