Paris Hilton and Britney Spears were clearly ahead of their time.

The heiress recently shared a few throwback pictures of herself with the pop star on Instagram. The photos show the two smiling wide for the camera and even puckering their lips for an early version of the duck face, with Hilton in a black tank top and silver chain locket necklace and Spears in a white collared button-up.

“17 years ago, Britney and I created the selfie! 👯‍♀️🤳🏻,” Hilton wrote in the caption. She concluded, “Tag me in your most epic selfies to celebrate the most iconic invention 🔥✨”

Fans immediately flooded the comments with praise for the throwback selfies. “You taught us so well…iconic 🌸✨💅🏼🥰,” one user wrote. Another added, “My life wouldn’t be the same without the selfie! Thank you xxx.”

Hilton recently lauded Spears for releasing her tell-all memoir, The Woman in Me, which officially dropped on October 24. “I know how hard it can be doing a memoir, because you have to really dive in and think about so many moments in your life that I’m sure you don’t even want to think about,” Hilton told People, recalling her own experience while writing Paris: The Memoir, which came out in March. “I am just proud of what a strong woman she is.”

Last month before its release, Spears reflected on the memoir as a form of catharsis following the end of her 13-year-long conservatorship. The singer told People, “It is finally time for me to raise my voice and speak out, and my fans deserve to hear it directly from me. No more conspiracy, no more lies—just me owning my past, present, and future.”