Kim Kardashian's birthday wish to sister Khloé Kardashian sparked controversy among fans.

Taking to Instagram on Thursday, Kim shared a heartfelt birthday post for Khloé.

In the caption, Kim wrote, "Welcome to the fucking 40 club baby!!!!! @khloekardashian I feel like you have been waiting for years to finally be done with your 30’s and the time has now come. I know this will be the best decade of your life filled with so much love and happiness! I’m so excited for you to experience this because I know how good it is, and no one deserves this more than you! What a crazy life we live! I couldn’t do it without you by my side!"

However, many fans expressed disappointment for Kim's appearance in the photo, accusing her of overshadowing Khloé.

One fan wrote, "And Kim is in every pic."

Another referenced Kourtney Kardashian's remarks about the SKIMS founder on The Kardashians, where she called her "narcissist" and said, "Anything you do, it's about you and about how it looks to the world about you."

The comment read, "Sometimes I wonder if Kim can ever post a tribute post to someone without herself in it every post she proves kourt’s point."

Despite the backlash, Khloé herself responded positively to Kim’s post, expressing, "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!!! You’re just everything and so much more!!!! Finally, I’m in the club!!!!! It feels great."