Joaquin Phoenix Couldn’t Stop Coughing During ‘Joker: Folie à Deux’ Production Due to Character’s Maniacal Laugh

Phoenix's co-star Harry Lawtey said the Oscar winner "would be coughing after each take."

Christian Bale’s voice as Batman in the “Dark Knight” trilogy is infamous — and infamously bad for the vocal cords — but as it turns out, Joaquin Phoenix‘s unhinged laugh as Arthur Fleck in the “Joker” films was also a bit of a health hazard.

Phoenix’s “Joker: Folie à Deux” co-star Harry Lawtey told Variety that the Oscar winner couldn’t stop coughing after doing Arthur’s maniacal chuckle.

“To watch him do that laugh and to see the effect on him — on everyone — blew my mind,” Lawtey said. “He would be coughing after each take. It was an education to watch him move through different flavors and shades of that performance.”

“Industry” star Lawtey plays Harvey Dent in the sequel film. District attorney Dent canonically becomes Two-Face in the comics, and was most recently played by Aaron Eckhart in “The Dark Knight.”

Lawtey added that Phoenix gave “a master class” in acting during the production. Phoenix was so committed to the role that he stayed in full makeup as the Joker as the cast workshopped a scene. And then he kept it on longer for a prank.

“Joaquin suggested, as a joke, that we FaceTime my mum and scare her,” Lawtey said. “My mum was in England, so it was quite late, and she was getting ready for bed. And I said, ‘Hello,’ and then I brought the phone up to my face, and Joaquin put his head on my shoulder. My mum screamed, ran away and woke up my dad.”

Phoenix’s dedication to the physicality of the role extended also to the dancing and singing sequences.

“I had this dream I was performing as Joker doing songs and I just called Todd because I thought there might be something there, and there wasn’t,” Phoenix said during the Venice press conference for the film’s world premiere. “Part of the joy for me was taking these songs that were standards and trying to find a way that it felt like they were specific to the characters, that it was the only way the characters could express themselves, with these songs sung in this way.”

Read the IndieWire review for “Joker: Folie à Deux” here. The sequel film debuts in theaters October 4.