Chadwick Boseman ensured co-star Sienna Miller was fairly compensated by donating part of his salary

Chadwick Boseman's untimely passing came as a gut-wrenching shock for all those who had the pleasure of working alongside him. While his loyal fans across the world mourned the loss of an actor whose cultural impact is simply unmatched, his former co-stars shared emotional tributes remembering the 43-year-old's remarkable character both on and off the screen. Now, almost exactly a month since the star's passing, Sienna Miller — who starred alongside Boseman in last year's cop thriller 21 Bridges — has come forth with a moving revelation about him that makes us love and respect him all the more.

Miller made the revelation while speaking to Empire magazine for the October issue, which "pays tribute to Chadwick Boseman, featuring personal remembrances from his collaborators, revisiting his iconic roles, and his Empire interviews." The 38-year-old revealed that Boseman, who was one of the producers of the movie, was instrumental in casting her for the role of detective Frankie Burns. "He produced '21 Bridges,' and had been really active in trying to get me to do it," she said. "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," Miller explained. However, she had her inhibitions about doing the project due to a couple of reasons. "I didn't know whether or not to tell this story, and I haven't yet. But I am going to tell it because I think it's a testament to who he was. 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," she said.

That was when Boseman went the extra mile to make sure that his co-star would be fairly compensated for joining the production. "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," Miller revealed.

Boseman's generosity and support came as quite a welcome surprise for the actress, who shares 8-year-old daughter Marlowe with ex-boyfriend Tom Sturridge, as it was unprecedented in the industry. "It was about the most astounding thing that I've experienced," she said. "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," Miller continued. "But there was no showiness, it was, 'Of course I'll get you to that number because that's what you should be paid.'" Boseman died on August 28 at age 43 after a private four-year battle with colon cancer, which he never spoke publicly about.