Her younger sister Kylie Jenner is famed for her cosmetically-enhanced lips, with the teenager admitting to having lip injections on their famous reality show, Keeping Up With the Kardashians in 2015.
But some fans are accusing supermodel Kendall Jenner, 21, of fiddling with her already perfect features in her latest Instagram snap.
Showing off her trim waist in a seductive pose while wearing a chequered bikini and white cropped T-shirt with her hair in a messy updo, Kendall sported a flawless make-up look with fake-lashes and fresh skin, but something about her face looked different.
One of her 89 million fans wrote: "Shes so hot but is it just me or does her face look different." Someone else said: "I hav a question has Kendall had plastic surgery ? Ps you look gorgeous."
Though it may be a subtle enhancement, Kendall's lips look a lot fuller than they did in pictures a few years ago.
Back in January, the model sent the internet into a frenzy after posting two photos showing bigger lips, with Kylie later stating on Snapchat that she had "overlined" her sister's lips that day.
Kendall also wrote on her app about the accusations, claiming that she loved the make-up look Kylie did for her.
She wrote: "When I deleted my Instagram back in November, people were saying: 'Kendall deleted her account to have full facial reconstruction!' I think they might have been referencing the day Kylie and I did a livestream for our book.
"We had to hurry, so I let Ky do my face. I never wear lipliner or lipstick unless it's the occasional obvious red. I left all of the makeup on because we were so rushed and I went out and did my thing. I LOVED my makeup. I never say this, but I just felt so pretty."
Someone else commented on the shot: "not natural. Lol many face lifts and procedures. She's scientifically beautiful and anyone can be."