Carrie Underwood celebrated her 36th birthday on Sunday (March 10), and her biggest fan ever was not about to let the occasion go by without a social media callout.

That super-fan would be her husband, retired NHL star Mike Fisher, of course—who posted a sweet photo of the two of them to Instagram for her special day.

"Happy birthday babe," he captioned the shot. "You're an incredible wife and mom! Us boys are so grateful for you! Love you lots."

The "boys" in question include not only Fisher himself, but the two youngest Fishers—sons Isaiah (who just turned 4 last month) and newborn baby brother Jacob (who made his debut in January).

Underwood has a nice start to age 36—aside, naturally, from Jacob's birth (which she counts as a miracle after suffering three miscarriages) the singer is getting ready for her Cry Pretty Tour 360  which will take her around the U.S. beginning on May 1 in Greensboro, N.C., across the pond to the U.K. for several dates starting in late June, and back domestically through the end of October. She'll bring Maddie & Tae and Runaway June out as opening acts for the duration of the U.S. leg.

See More Pics of Carrie Underwood's Tennessee Home:

Sign up for the Cat Country 107.3 Newsletter

Get the best of Cat Country delivered to your inbox every week.