Cillian Murphy Calls Oppenheimer Costar Emily Blunt 'One of the Funniest People': I Need 'Levity' on Set

Cillian Murphy took on a serious role for Oppenheimer, but he could look to costar Emily Blunt to find humor on set.

“She’s also one of the funniest people, and I have a rule that I can’t work unless there’s a lightness around the set,” Murphy, 47, recently told The Los Angeles Times of Blunt, 40. The pair costarred in Christopher Nolan's J. Robert Oppenheimer biopic last summer. Murphy took on the title character, while Blunt portrayed his wife Kitty Oppenheimer in a pair of performances that have each earned Golden Globe Award nominations to kick off awards season.

"There has to be some levity," Murphy told the outlet of how he likes his sets. "A lot of the films I do are quite heavy and go to some dark, challenging places, and you have to be relaxed to do that. So I don’t walk around in a state of f------ angst."

"I need to feel at ease. I can’t be in that dark place all the time," he added. "I don’t have the stamina for it.”

Much has been made of Murphy's performance in Oppenheimer — Blunt previously said that the actor "could only eat, like, an almond every day," in order to lose weight to portray Oppenheimer, while his other costar Robert Downey Jr. told PEOPLE that he "never witnessed a greater sacrifice by a lead actor in my career" while filming the movie.

Despite Murphy's status as a leading contender for the upcoming awards season, Murphy told the Times he views his own performance as "delicate and tiny, most of it."

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“I knew it would have to be a quiet, small performance, because the themes are f------ huge,” he said elsewhere in the interview. “What’s happening inside his heart and his mind can’t be painted big, particularly when it’s captured on an Imax camera and it’s going to be shown on a f------ 80-foot screen."

Oppenheimer has earned significant praise in the months since its release. In total, the film received eight nominations at the upcoming Golden Globes on Jan. 7; the only movie to garner more nominations at that awards show is Barbie. At the upcoming Critics Choice Awards, Oppenheimer received 13 total nominations — including acting nominations for both Murphy and Blunt.