When the cast for J.K. Rowling's upcoming play Harry Potter and the Cursed Child was first announced, certain fans were unhappy that a black woman would be playing the role of a grown-up Hermione Granger -- despite the fact that Rowling never specified Hermione's race in the books. The author has since responded to the minor backlash, and she's not mincing words.

“With my experience of social media, I thought that idiots were going to idiot,” she said in an interview with The Observer. “But what can you say? That’s the way the world is. Nova was chosen because she was the best actress for the job.”

And while Rowling says some dissenters tried to explain why they were upset about the casting, the author maintains their reasoning makes no sense.

"I had a bunch of racists telling me that because Hermione ‘turned white’ – that is, lost color from her face after a shock – that she must be a white woman, which I have a great deal of difficulty with," she continued. "But I decided not to get too agitated about it and simply state quite firmly that Hermione can be a black woman with my absolute blessing and enthusiasm.”

The show’s director, John Tiffany, cast Noma Dumezweni as Hermione, and said he was surprised by the reactions he read on Twitter.

"I am not as Twitter-familiar as Jo and Jack, so I hadn’t encountered its dark side, which is just awful," Tiffany said. "But what shocked me was the way people couldn’t visualize a non-white person as the hero of a story. It’s therefore brilliant that this has happened.”

Harry Potter and the Cursed Child takes place 19 years after the book series’ end, and the plot will follow Harry’s youngest son, Albus, who "must struggle with the weight of a family legacy he never wanted."

Previews begin at the London Palace Theater on June 7 but will officially open to the public on July 30.