Millie Bobby Brown stars in the new Netflix movie Enola Holmes, and the major gig came with some unexpected preparation.

The 16-year-old actress recently revealed that she essentially had to relearn how to speak with her native British accent for her role in Enola Holmes, according to Express. The film is set in London, and the Stranger Things star plays Sherlock Holmes’s little sister Enola.

During a recent interview, Brown, who was born in Spain but grew up in Dorset, England, discussed what it took to prepare for the upcoming film. The actress, best known for her breakout role as Eleven, admitted, "For the last five years, I’ve been playing an American character in Stranger Things and I found it really challenging being British in this, even though I am a Brit. I had to learn how to speak again because I’m so used to speaking in an American accent!"

As Express notes, this British film project came to be after Brown and her sister were inspired by the young adult book series by author Nancy Springer.

"The film was mine and my older sister Paige’s idea," Brown explained. "We fell in love with Enola after reading The Enola Holmes Mysteries and so we went to my mum and dad, who own a production company, and said, 'We’re so inspired by her. This needs to be a film.'"

Brown and her sister are also the producers for their passion project. The Enola Holmes star shared that “girl power” behind the scenes is just as important.

Enola Holmes is on Netflix now. We unfortunately still do not have a release date yet for Stranger Things season 4.