Tim Allen Reunites with Richard Karn to Film New History Show

Tim Allen and his good buddy Richard Karn are providing a sweet dose of nostalgia for '90s kids ... filming together again for a show they'll co-host together.

The "Home Improvement" stars are working together again for the competition show "Assembly Required" on the History channel. Richard was so excited about the reunion, he posted a pic. If you have any doubts about how much fans wanna see 'em back together -- it racked up nearly 20,000 likes in just a few minutes!

Tim might have given just a smirk for the pic, but he's been excited about this since back in August when he announced they were gonna be doing the show. As he put it then, "I created a competition show with @History and my old buddy @TheRichardKarn to challenge the people who love to get stuff done!"

The series -- which doesn't have a premiere date yet -- will feature builders from across the country who are tasked to fix all kinds of household items.

For those of you too young ... Tim and Richard's "Home Improvement" was a hit sitcom on ABC from 1991 to 1999. Since then, Richard has guest-starred on Tim's "Last Man Standing" -- but this new series is the closest we've come to a "Home Improvement" reboot.