(Pearl Mackie as Bill Potts in ‘Doctor Who.’ Screenshot via the BBC.)

“Doctor Who” will introduce the first openly gay lead companion in the show’s history in its upcoming season.

Bill Potts’ sexuality will be made clear in her second line of dialogue, according to the BBC.

“It shouldn’t be a big deal in the 21st Century. It’s about time isn’t it?” Mackie, 29, told the BBC. “That representation is important, especially on a mainstream show.”

“[Being gay] is not the main thing that defines her character – it’s something that’s part of her and something that she’s very happy and very comfortable with,” Mackie continues.

“Doctor Who” first aired in 1963. The show has included LGBT characters before, including reoccurring characters River Song and Jack Harkness, since its modern revival in 2005. The Doctor’s permanent companions, which have included Billie Piper, Jenna Coleman and Karen Gillan, usually develop a romantic interest or flirtation with him while on their travels. While Bill being the first permanent companion to be gay will change the dynamic, Mackie says the representation should be normalized.

“It’s important to say people are gay, people are black – there are also aliens in the world as well so watch out for them,” Mackie says.

“Doctor Who” premieres on April 15 at 9 p.m. on BBC America.