“We loved each other but barely knew each other. Today, we know each other really well and still love each other,” Curtis wrote in her Instagram tribute

Christopher Guest and Jamie Lee Curtis arrive at a screening of Netflix's "Mascots"; Jamie Lee Curtis Celebrates 40th Wedding Anniversary with Husband Christopher Guest

Christopher Guest and Jamie Lee Curtis in Los Angeles on Oct. 5, 2016 (L) and on their wedding day (Dec. 18, 1984). Photo: Amanda Edwards/WireImage; Jamie Lee Curtis/Instagram

Jamie Lee Curtis and Christopher Guest are celebrating a big marriage milestone.

On Wednesday, Dec. 18, the Last Showgirl actress marked 40 years since she wed Guest with a sweet Instagram tribute. The post began with a black-and-white throwback photo from their wedding day in 1984. The second snapshot showed the couple’s shadows on the ground — hand in hand, mirroring their wedding picture.

“40 years ago today, on a rainy Tuesday afternoon at 4:30, Christopher and I married,” Curtis, 66, captioned her post. “We loved each other but barely knew each other. Today, we know each other really well and still love each other.”

She continued on to say that she and Guest, 76, have “been through a lot and have raised and loved two beautiful daughters and started many new careers and weathered the myriad storms of life on life’s terms of loving and loss.”

She concluded, “We held hands that day as we walked back down the aisle and we’re still holding hands today. I guess the beginning of ‘my hand in yours.’ The long and winding road.”

Curtis’ heartfelt tribute was accompanied by The Beatles track, “The Long and Winding Road.”

Last week, Curtis opened up about being married to Guest for nearly four decades during an appearance on the Today show, Dec. 12.

On the talk show, the Academy Award winner spoke about the joy that Guest continues to bring to her life as they approached their 40th anniversary.

“Do you guys just keep growing together?” Hoda Kotb asked Curtis.

“It is that,” the actress replied. “Ultimately, Chris wasn’t a director when I married him, I wasn’t a writer. Chris wasn’t a producer when I married him, I wasn’t a producer when he married me. We have grown into these new jobs that we’ve done.”

Curtis went on to describe how Guest enriches her life. “He still makes me laugh more than any human being, and I’m sure there’s something about me that he likes,” she said.

Jamie Lee Curtis Celebrates 40th Wedding Anniversary with Husband Christopher Guest.

Jamie Lee Curtis and Christopher Guest.Jamie Lee Curtis/Instagram

Curtis tied the knot with Guest after six months of dating. They went on to welcome two children: daughters Annie, 38, and Ruby, 28.

During a Dec. 2 appearance on Jimmy Kimmel Live, Curtis said she had recently found the Cartier receipt from when her now husband bought her engagement ring.

“He was shooting SNL in New York and I was shooting the movie Perfect,” the Halloween actress recalled. “I was on something called a payphone where you put quarters in and I remember we were speaking and I said, ‘What did you do today?’ “

Guest told her he “went for a walk” around the city and mentioned that he visited a Cartier store.

“And then in typical boy fashion, [he asked,] ‘Do you like diamonds?’ ” Curtis continued. “So then he came out to Los Angeles and … well, he proposed in a more private and intimate way.”