Serena Williams is celebrating four decades, and her husband Alexis Ohanian made sure she spent her birthday feeling loved and more special.

The tennis superstar’s husband took social media to pen a romantic message. “✨ the incomparable @serenawilliams - grateful for every minute I get with my amazing wife & Olympia’s mama,” he wrote on Instagram.

In the past, Ohanian has shared how impressed and proud he is of Williams’s ability to balance motherhood and her work.

“What she hit on the head was the fact that I had a kind of a warped view of the path to excellence and the path to greatness being a direct result of just pure work,” the 38-year-old entrepreneur told CBS This Morning.

“One thing that I’m still working on is balancing that with time off, with time away, with time to reset and recharge and something she’s really good at is shutting it off and focusing on family time or personal time,” he explained. “I’m always a smart phone away from dipping back into a term sheet or dipping back into work.”

“I certainly still get checked from time to time on that one,” the businessman said, “because it’s something that I want to be my best. I think we all do.”

While Alexis and Serena are always speaking highly of one another, they also have their ups and downs. Earlier this year, the four-time Olympic gold medalist admitted that their marriage consists of a lot of work.

“Marriage is not bliss,” she said with a laugh during Bumble’s The Question Game when asked what was the most surprising thing she learned about the lifelong commitment. “But it can be if you work at it.” She went on to add that “a dealbreaker for me in a relationship is definitely loyalty. Well, not having it, that is.”

Williams went on to offer some advice for anyone dealing with a broken heart, saying, “Heartbreak is a part of life, whether it be a loved one, a boyfriend, or an animal...But time heals all wounds.”