Mariska Hargitay Celebrates 18th Anniversary with Peter Hermann: 'Grateful'

Mariska Hargitay is celebrating her love.

In honor of her 18th anniversary with husband Peter Hermann, the Law & Order: Special Victims Unit star shared an Instagram tribute on Sunday to commemorate the occasion.

The first photo Hargitay, 58, shared was a black and white shot from the twosome's wedding day. She was pictured sitting on Hermann's lap with a giant smile on her face.

The actress also included a second, more recent image edited in black and white, showing Hargitay lying in Hermann's arms as they were on a boat.

"Eighteen years. Grateful," she captioned the photos. "In love. Together."

RELATED: Mariska Hargitay Recalls Magical First Date with Husband Peter Hermann: 'I Just Started Sobbing'

Hargitay tied the knot with Hermann, 55, in 2004. The pair have three children together: Amaya Hermann, 11, August Hermann, 16, and Andrew Nicolas Hargitay Herman, 10.

The couple previously told PEOPLE laughter is one of the reasons their marriage stays so strong. "I never thought I would have this much laughter in my life," Hermann said.

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"Not just actual laughter," he continued. "But also the way that Mariska is just the embodiment of laughter — of joy."

Though their marriage is not free of tough moments, Hermann said laughter is the couple's uniting force. "It's the way we find our way back to each other," he says. "It's this fantastically, wonderfully ridiculous way that we can swing back and forth any number of times in any given day. But fundamentally we know we have the same destination."

RELATED: Mariska Hargitay and Peter Hermann Reveal Laughter Is the Key to Their 15-Year Marriage

Mariska Hargitay/Instagram

"We know where we're headed, and it's good," he added. "And we know we'll get there together."

Hargitay and Hermann met on the set of Law & Order: SVU in 2002. She previously recounted their first date to PEOPLE, recalling her incomparable connection to Hermann at the time.

While at church on the date, Hargitay even got emotional. "I just started sobbing. Peter thought I was crying because I was so moved by the service," she said. "No, it was because I was just overwhelmed, realizing he was the one."