Todd Phillips is open to a “Joker” sequel starring Joaquin Phoenix but it would have to be done for the right reasons.

Phillips’ dark take on the classic Batman villain took the world by surprise, so it should come as no surprise that a sequel is being discussed. Phillips is open to the idea if he can conjure a story as impactful as the first film.

RELATED: Original ‘Joker’ Ending Had A Grim Fate For Bruce Wayne

“When a movie does $1 billion and cost $60 million to make, of course, it comes up,” Phillips told the crowd at Deadline‘s The Contenders event. “But Joaquin and I haven’t really decided on it. We’re open. I mean, I’d love to work with him on anything, quite frankly. So who knows?”

“It would have to have a real thematic resonance the way this one did, ultimately being about childhood trauma and the lack of love, and the loss of empathy,” he continued. “All those things are really what made this movie work for us, so we’d have to have something that had an equal thematic resonance.”

RELATED: AFI Names ‘Joker,’ ‘Jojo’ Among Top 10 Films Of The Year

Phillips admits he never expected this level of success from the Phoenix-led film: “None of us thought an R-rated movie could do over $1 billion across the world.”

“I think the themes in it really resonated,” he said. “It’s pretty obvious what was happening in our country in 2017 while we were writing it, and really wanted to use Joker to make a movie about the loss of compassion and the lack of decorum in the world.”