Jon Gosselin and Kate Gosselin can officially put a one in front of the eight.

Here’s some news that may make you feel old: The reality stars’ six youngest kids Aaden, Collin, Joel, Alexis, Hannah, and Leah turned 18 years old on May 10. (Yes, you read that right!) And to celebrate the occasion, Jon shared a throwback photo of the sextuplets to Instagram Stories, writing, “Happy 18th birthday! Today is your birthday we gonna say it loud. I love you, Love Dad.”

The former couple—who are also parents to 21-year-old twin daughters, Cara and Madelyn—welcomed their sextuplets in 2004, just three years before the premiere of their TLC series, Jon & Kate Plus 8. (The pair divorced in December 2009, one month after the network announced the cancellation of their show).

Although Kate and the rest of the family haven’t posted on social media in honor of the big day just yet, Hannah revealed to InTouch Weekly that she recently had a “dream” birthday bash in Miami.