Sarah Michelle Gellar and Freddie Prinze Jr. celebrated 20 years of marriage on Thursday.

The "Buffy the Vampire Slayer" actress noted the day on Instagram and shared a few photos of the couple.

Gellar also joked to Howard Stern, who asked Prinze Jr. more than 20 years ago "if he 'will marry Sarah Michelle Gellar even though you know that it won't last?" (Prinze Jr. told Stern it would.)

Stern then bet him that the marriage wouldn't last 10 years.

"You're gonna hunt me down and go, "Howard, I owe you money,"' Stern said at the time.

The two actors met while filming "I Know What You Did Last Summer" in 1997 and started dating in 2000. They became engaged a year later.

They married in a ceremony in Puerto Vallarta, Mexico in 2002.

The couple shares two children together, 12-year-old daughter Charlotte and a 10-year-old son, Rocky.