'That '70s Show' Stars Celebrate 20-Year Anniversary with the 'Ultimate #TBT'

That ‘70s Show just turned 20!

To celebrate the occasion, Topher Grace, who played Eric Forman on the series, tweeted a photo of the cast for an “ultimate #tbt.”

“Hard to believe That 70s Show premiered 20 years ago today. Few people can say they owe everything to one small group, but in my case it’s true,” the 40-year-old wrote. “To quote the ‘78 Point Place High yearbook ‘What a long strange trip it’s been… in Forman’s basement’ #hellowisconsin.”

Laura Prepon, who played his love interest Donna Pinciotti, also tweeted a photo of the crew during the 1990s.

“#ThrowbackThursday to the first press tour for #That70sShow – we were all blown away when we saw this bus,” the actress, 38, wrote. “Can’t believe the show came out 20 years ago today…such a special group of people. So lucky to have been a part of it.”

Last week, the Orange Is the New Black actress posted another throwback photo with Grace from when they starred on the show and were “babies.”

And Wilmer Valderrama paid tribute, too.

“August 23, 1998, 20 years ago today,” he tweeted. “This was the first picture we ever took together, we had just met and had no idea what was ahead of us or if it would even last. but we knew it was gonna be fun. 8 years and 200 episodes together.”

Earlier this year, Grace told PEOPLE that he’d be willing to reboot the show “in a heartbeat.” (He left the series early after season 7.)

“Mostly just to hang out with everyone ’cause it’s such a great group of people and I miss them so much,” Grace said. “I love that group. I thought I was lucky to get the part, but I now realize I was really lucky to get a part that was with that group of people.”

The show, which first aired on Aug. 23, 1998, and ended in 2006 after eight seasons, was nominated for 16 Primetime Emmy Awards. It also starred Mila Kunis, Ashton Kutcher, and Danny Masterson.

Kunis, 35, and Kutcher, 40, whose characters Jackie and Kelso dated during the show, ended up getting married real life in 2015 and now have two children together — 3½-year-old daughter Wyatt Isabelle and 21-month-old son Dimitri Portwood . The Two and a Half Men actor was actually Kunis’s first kiss, too!

Kunis celebrated her birthday earlier this month, and a source told PEOPLE that the two are still deeply in love.

“They are real people and have found true love, trust, friendship and honesty. They are a great example for others to follow,” the source told PEOPLE.

Congratulations to the cast, and perhaps the crew will say “Hello Wisconsin” at a reunion soon!