The Vampire Diaries‘ Stefan and Damon Salvatore could relish in glasses of whiskey but Ian Somerhalder and Paul Wesley can’t say the same about tea.

The duo is opening up about the “most insane anxiety issues” they faced while filming season one of the Julie Plec- and Kevin Williamson-created series due to all the caffeine that they were drinking. During a party Tuesday for the pair’s whiskey brand Brother’s Bond Bourbon and the Tennis Channel, they told Page Six that they drank a lot of iced tea in scenes where it was supposed to appear they were drinking whiskey.

The Star Trek: Strange New Worlds actor, you played Stefan on The CW’s hit show that ran for eight seasons, recalled drinking an ample amount of tea “take after take” on set.

“You’re drinking 20 to 30 cups of tea, so by the end of the day you’re, like, ‘Ahh!,’” the V-Wars actor, who played Damon in the series, added. “We didn’t [sleep].”

After filming the first season, the cast and crew found a solution, since they couldn’t drink actual alcohol while shooting. Wesley said they “switched to decaf, so we felt a lot better.” Somerhalder added that they also drank “herbal tea” for the remaining seasons.

The supernatural teen drama, which aired from 2009 to 2017 and launched several spinoffs, followed Stefan and Damon, two vampire brothers in love with the same girl, Elena Gilbert (Nina Dobrev). While torn between the two of them, Elena finds herself in a world she never could have imagined that’s full of love and passion but also death, danger and mystery.