If her latest film Free Fire is any indication, Brie Larson can definitely hold her own in the boy’s club. Not only is she the only woman in the entire cast, she’s also the brains begin the entire operation, brokering a dangerous black market arms deal between two groups of seriously shifty men.

When things go awry (as they often do in these cases), all parties end up ducking for cover, which means that the Oscar winner and co-stars Armie Hammer, Cillian Murphy, and Sharlto Copley spend the majority of the film running, diving, and crawling around a deserted warehouse. And if that wasn’t hard enough? Larson does it all in heels. Stacked heeled knee-high boots, to be exact.

“The film is set in the 1970s, so my wardrobe was one of the big things that helped me get into the mind of my character Justine,” Larson told InStyle when the film, which is executive produced by Martin Scorsese, premiered at the Toronto International Film Festival last fall.

VIDEO: Watch the Free Fire Trailer

With a paisley top, printed scarf, tailored blazer, and high-waisted jeans already in place, Larson says the shoes were the finishing touch. “My go-go boots were the most important piece because they affected the way that I moved and walked in every scene. Since there’s very little dialogue in the movie, the physicality of our characters became that much more important.”

And now, after logging hours on the Free Fire set, Larson claims to have walked away with a new skill. “It’s funny because I don’t wear heels a lot in my day-to-day life, but I definitely know how to run in them now,” she says. “But I’m still always going to be that person wearing sneakers at the after party. Some designers give me sneakers now just for that reason. I guess I turn into a pumpkin quicker than everyone else.”

Free Fire is in theaters on April 21.