Los Angeles, California - Kim Kardashian posted for her sister Khloé Kardashian's birthday on Thursday amid their feud being aired on the latest season of The Kardashians.

"Welcome to the f**king 40 club baby!!!!!" the American Horror Story actor wrote alongside some matching glamor shots of the two sisters.

Kim gushed with excitement for Khloé to experience the joys of her 40s "because I know how good it is, and no one deserves this more than you!"

"I couldn’t do it without you by my side," she added.

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"Thanks for being the best friend and sister a girl could ever dream of... Happy Birthday."

Khloé responded to her big sister's post in the comments, writing, "I love you my keeks!!!! You are the most incredible human being and I feel so blessed I get to have to you by myside!!!"

KoKo continued, "You’re just everything and so much more!!!! Finally, I’m in the club!!!!! It feels great."

The ongoing sisterly dispute from season 5 of Hulu's reality TV hit The Kardashians seems rooted in mutual mom-shaming, although Khloé has also admitted that she doesn't appreciate her family's scrutiny over her love life.

Kim was previously embroiled in a knock-down-drag-out rift with sister Kourtney Kardashian, although they have since made up and things are reportedly "back to normal" between the two.

Maybe the same is true of Kim and KoKo!

Momager Kris Jenner and Kourtney also posted in honor of Khloé's day, with the birthday girl herself posting Insta Story shoutouts over all the presents and flowers she received.

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She also posted some sweet clips of a birthday pool party for all the Kar-Jenner cousins.

Happy 40th, Khloé, and here's to many more!