Turns out not everyone is a fan of “Barbenheimer,” the term coined for the box office showdown that will take place when Oppenheimer and Barbie premiere in theaters together July 21.

Oppenheimer director Christopher Nolan finally revealed his thoughts on Warner Bros.’ Barbie sharing a release date with his war-time epic, which comes from Universal Pictures. Though his diplomatic answer doesn’t hint at anything going on behind the scenes, multiple sources said the joint release date “upset” the director, according to Insider.

“Those who care about the theatrical experience, we’ve been longing for a crowded marketplace with a lot of different movies,” he said, per Insider. “That’s what theaters have now, and those of us who care about movies are thrilled about that.”

Sources said Nolan was “upset” that Warner Bros. scheduled Barbie to premiere during what has become known as “Nolan’s weekend” in the industry, Insider reports. He’s long preferred to release his films during that mid-July period since 2008’s The Dark Knight.

The report also claimed Warner Bros. was asked to move the Barbie release date, but the studio refused.

Insider pointed out that Nolan previously blasted Warner Bros. for the studio’s controversial decision to release its 2021 films on HBO Max.

“Some of our industry’s biggest filmmakers and most important movie stars went to bed the night before thinking they were working for the greatest movie studio and woke up to find out they were working for the worst streaming service,” he said in a statement at the time, per The Hollywood Reporter.

When asked by Insider if he felt his statement had at all influenced Oppenheimer‘s premiere date, Nolan reportedly laughed and told the outlet, “Now, you must know I’m not going to answer that question.”

Despite his feelings, the trending joke could be driving ticket sales — AMC has reportedly already sold 20,000 tickets to both films so theater-goers can enjoy their own double-feature.

Oppenheimer and Barbie will land in theaters on July 21.