Sienna Miller has revealed that Chadwick Boseman reduced his own salary for "21 Bridges" to get her on board the project and ensure she felt fairly compensated.

In a new interview with Empire, Miller said she was sharing the story publicly for the first time because "it's a testament to who he was." Boseman privately fought a battle with colon cancer for four years before his death in August.

Boseman, who also produced "21 Bridges," liked Miller's work and wanted her for the role of detective Frankie Burns, she told the publication.

"He produced '21 Bridges,' and had been really active in trying to get me to do it," Miller said, adding, "He was a fan of my work, which was thrilling, because it was reciprocated from me to him, tenfold. So he approached me to do it, he offered me this film, and it was at a time when I really didn't want to work anymore. I'd been working non-stop and I was exhausted, but then I wanted to work with him."

Boseman fought for Miller.

"This was a pretty big budget film, and I know that everybody understands about the pay disparity in Hollywood, but I asked for a number that the studio wouldn't get to. And because I was hesitant to go back to work and my daughter was starting school and it was an inconvenient time, I said, 'I'll do it if I'm compensated in the right way.' And Chadwick ended up donating some of his salary to get me to the number that I had asked for. He said that that was what I deserved to be paid."

She called his gesture "astounding."

"That kind of thing just doesn't happen. He said, 'You're getting paid what you deserve, and what you're worth.' It's just unfathomable to imagine another man in that town behaving that graciously or respectfully. In the aftermath of this I've told other male actor friends of mine that story and they all go very very quiet and go home and probably have to sit and think about things for a while. But there was no showiness, it was, 'Of course I'll get you to that number, because that's what you should be paid.'"