Catherine Zeta-Jones and Michael Douglas shared Valentine's Day tributes to each other Monday on Instagram.

Zeta-Jones shared a photo of the couple wearing all-white to her personal Instagram. 

"Happy Valentine’s Day to my honey! Love you," she captioned the post.

Meanwhile, Douglas shared his own photo of the two dressed up.

Michael Douglas Catherine Zeta Jones

Catherine Zeta-Jones shared a Valentine's Day tribute to husband Michael Douglas on Instagram.

CATHERINE ZETA-JONES CREDITS ‘CONSTANT LOVE AND RESPECT’ FOR HER 21-YEAR MARRIAGE TO MICHAEL DOUGLAS

"Happy Valentine’s Day to my darling Catherine! I love you always and forever," he captioned the post.

Zeta-Jones and Douglas tied the knot in 2000. The couple celebrated 21 years of marriage in November.

The actress previously revealed the secret to their successful marriage is their strong connection.

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Michael Douglas Catherine Zeta Jones

Douglas shared his own tribute to Zeta-Jones on his personal Instagram. (Ben Curtis/PA Images/PA Images via Getty Images)

"My husband and I spend a lot of time together because, unlike so many couples, we've never had a 9-to-5 job where it's consistent," she told WSJ magazine. "We're either on or we're off. I'm really working 16 hours a day or I'm not. He's doing the same or not. So we've had in our relationship huge amounts of time where we've been just us."

This isn't the first time the two have shared tributes to each other on social media. 

Douglas and Zeta-Jones share the same birthday, Sept. 25, and this past year shared posts for each other.

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Michael Douglas Catherine Zeta Jones

Douglas and Zeta-Jones celebrated 21 years of marriage in November. (Getty)

"Happy Birthday to me. Happy Birthday to him, Happy Birthday to my husband and his wife, Happy Birthday to me, and me, and me, and Michael," Zeta-Jones captioned her post.

"Here's to more years that we can celebrate September 25th together," she added. "Love you."