Neil Patrick Harris Celebrates His Twins' 11th Birthday: 'Truly Remarkable People'

Neil Patrick Harris is wishing his twin children a very happy birthday.

On Instagram Tuesday, the How I Met Your Mother actor, 48, celebrated daughter Harper Grace and son Gideon Scott — whom he shares with husband David Burtka — on their 11th birthday.

"Happy 11th Birthday, Harper and Gideon. You continue to illuminate our world with your spirits, and are growing into truly remarkable people," Harris wrote of a sweet photo of the kids sitting side by side on a boat.

The proud dad continued, "Thank you for pushing yourselves, for protecting each other, and for making your father and I laugh, melt, and marvel. You're the best things in our very fortunate lives. We love you both in every way, and without conditions. ❤️❤️ #happybirthday #proudparents."

On his own birthday in June, the proud father even dedicated his celebration to his children, calling the twins his "two favorite gifts."

"Today's my birthday. These are my two favorite gifts. #grateful #48," Harris wrote under the heartwarming snap, wearing a gold crown while holding his kids close.

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The actor previously spoke about his love for his kids and a favorite family tradition in an interview with PEOPLE.

In April, Harris explained that he and Burtka, 46, look forward to taking Harper and Gideon to Walt Disney World around Christmas each year, a tradition he hopes to keep until his twins "can't stand" him.

"Our kids have grown up appreciating and valuing not only the amusement rides, but the architecture and the Imagineering that goes on, both in front and behind the scenes," the star said.

"So I still look back on how that has been an important part of their lives and I can't wait to continue it until they can't stand me anymore," he teased.