Mormon dietary restrictions trace their origins to Scripture and what’s called the “Word of Wisdom,” which the faithful interpret to prohibit things like coffee, tea, and alcohol. The Word of Wisdom doesn’t mention anything about caffeine, but Steve Evans, founder of the Mormon blog By Common Consent, told BuzzFeed News that members of the church are “naturally inquisitive, and some have engaged in their own sort of rabbinical analysis of why no coffee or tea.”

“Their answer: caffeine, of course,” Evans said. “So this led to a small but vocal group banning caffeinated drinks.”

Though the church clarified in 2012 that caffeine was not prohibited, the belief has persisted. It’s unknown how many Mormons actually avoid caffeine, but Evans said everyone was familiar with the idea.