It turns out Kendall Jenner has known about Caitlyn Jenner's desire to become a woman for a very long time.
The 19-year-old supermodel gets candid about her father's transgender status in a new interview with WWD, including the fact that it was a bit of an open secret growing up.
"It's an adjustment. It's something you have to get used to. But I've known since I was a kid," Kendall reveals. "He never confirmed it to me, but I’ve known for a very long time. It's the same person."
WATCH: Kim Kardashian Reveals Her Father, Rob Kardashian Sr., Heard Rumors About Caitlyn Jenner Before Her Transition
Still, although she's undoubtedly been supportive of her father, she admits she did feel a sense of loss when Bruce Jenner became Caitlyn Jenner.
"My dad says it herself sometimes, it's kind of like mourning the loss of someone, because it is," Kendall says. "My dad is my dad, but he’s not there physically anymore. But she lets me call her dad -- that's the last little piece of dad I've got."
Kendall points out to the publication that her pronoun usage changes based on what point of Caitlyn’s life she's referring to.
Caitlyn and Kendall still have a close relationship to this day. Just last week, Caitlyn Instagrammed a sweet pic of the two cuddling, writing, "So great spending time with @KendallJenner! Love my little girl."
Kendall's big sister, Khloe Kardashian, also revealed in July that she and her famous siblings still refer to Caitlyn as "Bruce."
"We don't like to say that Bruce is gone per se," the 31-year-old reality star told Australia's The Project. "We, my sisters and I, we will call Caitlyn 'Bruce' and we've been told that's completely fine. … And she has told us, we are allowed to call her any name we want to."
Meanwhile, along with Kendall, Kim Kardashian also recently talked about being one of the first in the family to know about Caitlyn's identity as a transgender woman on her new website.
"I came home from a friend's house and walked into the garage and Bruce was there, dressed up as a woman. Heels, wig, makeup and all!" Kim, now 34, recalled. "I don't remember specifically what he had on because I put my head down and ran into my bedroom."
"For over a decade, we assumed he was a cross-dresser, not transgender," Kim added.
WATCH: Kylie Jenner Gets Visit From Caitlyn During Her Makeup Tutorial
While Kendall and her sisters are adjusting to life with Caitlyn, Kendall has remained tightlipped about the transition. In a recent interview with ET, Kendall did not discuss her parents, though she did open up about her dating life.
"I don't know, I just like to keep my private life private," Kendall told ET about keeping her dating life on the down low. "I try my best, but at the same time, I try not to let being out with someone affect my everyday life. Like, if I want to go out and grab a smoothie with a friend who's a male, I'm not gonna let the paparazzi stop me from doing that and living my life and just being a normal person."
Watch more of her candid chat with ET as Kendall opens up about her adorable niece, 2-year-old North: