Jojo Rabbit‘s script ended up on the Black List, and the movie has popular filmmaker Taika Waititi at the helm. Yet the dark comedy set in Nazi Germany wasn’t exactly an easy sell for Fox Searchlight, and the studio might not have made the movie at all had Waititi turned down the critical role of an imaginary Adolf Hitler. In a new interview, Waititi reveals that the studio had to pitch him on the idea of playing the part, primarily because they felt that it needed to be handled in a specific way that only Waititi himself understood.

I loved Jojo Rabbit when I saw it at TIFF, but some critics seem altogether mixed on Taika Waititi’s “anti-hate satire.” I get it – the movie is dealing with tricky subject matter, and the tone – which is a mix of comedy and melancholy – isn’t going to work for everyone. Still, I think Waititi did a remarkable job making a potentially disastrous premise – a young boy in Nazi Germany has Hitler for an imaginary friend – work, and work well. Part of that has to do with Waititi’s writing and directing, but another big part is his performance as the imaginary Hitler. And it almost didn’t happen.

For one thing, Hitler almost wasn’t in the movie at all. In an interview with Business Insider, Waititi reveals that “The very first draft didn’t have him, but then I started all over again.” Jojo Rabbit is an adaptation of Caging Skies by Christine Leunens, but Leunens’ book isn’t comedic, and Waititi’s first draft of the script was truer to that – and thus a far more serious film.

“Knowing myself, I knew eventually I was going to put humor into it somewhere,” Waititi says. “When I rewrote it, I just started typing and it just kind of wrote itself. It only took me a couple of weeks. And I don’t usually start at page one but I started and basically wrote all the way through. And the Adolf character came about and the script hasn’t changed that much since. It’s really hard to explain because the only time it’s really happened to me is with this script.”

Waititi goes on to add that Fox Searchlight only wanted to make the movie if he agreed to play Hitler. “They came in and said they really loved the script,” he says. “This is four or five years after I wrote it. They said they really want to make it but they said, ‘We’re only interested if you play Hitler.’ Which was lunacy to me.”

The writer-director-actor goes on to explain Searchlight’s reasoning, adding that it made a certain sense after he thought about it:

“They made a good point which was that particular role is written a certain way and it needs to be handled by the person who invented that character. Part of it, like we said, is the celebrity distraction thing, but also because the way I wrote it, and because I knew how it needed to be played, it fell on me. And it actually made it easier to play because I didn’t have to deal with someone else filtering what I was trying to do. They were right, looking back on it. If I worked with another actor maybe that person would have researched it too much or tried to do a more authentic version of Hitler and pulled away the buffoonery I was after.”

Jojo Rabbit opens in select theaters October 18.