Cillian Murphy and Robert Downey Jr. might play adversaries in Oppenheimer, but the two actors can’t stop saying enough nice things about each other in real life.

In separate interviews, the stars of Christopher Nolan‘s newest movie opened up about their on-screen personas, and their admiration of each other off screen.

Keep reading to find out more…

In his interview with GQ, which was done before the strike, Cillian praised Robert‘s performance.

“I mean, acting with him was just extraordinary,” he shared with the magazine. “He’s just electrifying, the most available, engaged, present, unpredictably brilliant actor I’ve ever worked with.”

Meanwhile, Robert told People that he was impressed by Cillian going to such lengths to play the real life physicist.

“He knew it was going to be a behemoth ask when Chris called him,” he shared during the interview. “But I think he also had the humility that is required to survive playing a role like this. We’d be like, ‘Hey, we got a three-day weekend. Maybe we’ll go antiquing in Santa Fe. What are you going to do?’ ‘Oh, I have to learn 30,000 words of Dutch. Have a nice time.’ But that’s the nature of the ask.”

Robert added, “I have never witnessed a greater sacrifice by a lead actor in my career.”

Oppenheimer is out in theaters now.

If you’re wondering, here’s how the blast in Oppenheimer was pulled off.