Kim Kardashian West is sticking up for mom Kris Jenner.
In a sneak peek clip from Sunday's all-new episode of Keeping Up With the Kardashians, the reality star and her oldest sister, Kourtney Kardashian, discuss Caitlyn Jenner's memoir, The Secrets of My Life, which Kim says "discredits" the momager.
WATCH: Caitlyn Jenner Shares 'Secrets of My Life' in New Memoir: 6 Shocking Revelations
The clip begins with Kourtney asking Kim if she read the whole thing. "'Cause I was thinking, 'Is mom exaggerating and making it a big deal?'" she says.
In a previous episode of KUWTK, Kris revealed that she was "so angry" by her portrayal in the book, saying "everything was made up" and "nothing makes sense."
Kim backs up her mom and explains to Kourtney that "[Caitlyn's] so angry at mom, like for no reason."
"It was like, 'I didn't speak to my sister because of Kris. I didn't see my kids because of Kris,'" she explains. "Like, grow up and say, 'I didn't call my kids!'"
Kim continues on, telling Kourtney that Caitlyn claims she never saw "a dime" of her money when they were together.
"[Caitlyn] was insinuating that mom took the check and pocketed it and had this huge savings," Kim says. "The money wasn't going in mom's pocket."
"They made the money together," adds Kourtney. "Even when mom would book appearances, I worked for her, I would hear her phone calls in the office. She would hustle to get speeches. She changed Caitlyn's career and she made her have this motivational speaker business."
WATCH: Kendall Jenner Reacts to Caitlyn Jenner's Memoir on ‘KUWTK’: ‘That’s Insane!’
Kendall Jenner's reaction to the memoir aired on last week's episode of KUWTK, and was very similar to how her sisters felt.