The 22-year-old model snapped a series of selfies with Kylie while wearing matching makeup with the 20-year-old television personality on set.
Kendall shared a slideshow on Instagram of herself and Kylie posing for the camera. The sisters both wore sun-kissed makeup looks and square-neck crop tops with thin straps.
"alien sister @kyliejenner," Kendall captioned the post.
Kylie shared similar photos with Kendall on her own account.
"love u sister @kendalljenner," she wrote.
Kendall and Kylie star on their family's E! series Keeping Up with the Kardashians and also have a clothing line together. Kendall recently told Elle she's grown closer to Kylie since the 20-year-old welcomed her first child, daughter Stormi, with Travis Scott in February.
"It's obviously a bit weird that your little sister is having a baby before you. I didn't expect it to happen like this. But it's beautiful," the model said.
"It's brought us closer together," she added. "We've always been very close, but we would butt heads all the time. This has made her a bit more loving toward me."
Kylie shared details about her whirlwind relationship with Scott in an interview with GQ published Tuesday. She said she abandoned her life in California to follow Scott on tour after meeting the rapper at Coachella music festival.