Meghan Markle and Prince Harry’s son, Archie, just turned six this week, and to celebrate, the Duchess of Sussex shared a sweet photo of him.

In the picture, Archie is seen standing on a balcony, looking away from the camera. He seems to be watching a beautiful sunset in the distance. Meghan wrote next to the photo:

“Our son. Our sun.

Happy 6th birthday to Archie!

Thank you for all of the love, prayers, and warm wishes for our sweet boy. He’s six! Where did the time go?

(And for all of you who came to celebrate with us at his party last weekend, thank you for making his birthday so incredibly special).”

According to DailyMail.com, there was one small detail Meghan left out of the caption, which some people noticed — especially after some recent criticism.

In her message, Meghan simply called him “Archie” instead of using his full royal title, “Prince Archie.”

Royal watchers may remember that Prince William and Kate Middleton usually include their children’s titles in birthday posts.