Taylor Swift’s “1989″ has already received glowing reviews, and despite the fact that the album isn’t out until Monday, we think we know the singer-songwriter’s secret weapon.

For the upcoming album, Swift collaborated with Bleachers frontman Jack Antonoff on “Out of the Woods,” as well as the songs “I Wish You Would” and “You Are In Love.” That last song is a bonus track off the deluxe album and actually about Antonoff and his girlfriend, Lena Dunham. The connections between Antonoff and Swift don’t end there: he sat down with Swift to interview her for MTV and revealed one of her weird quirks in the process.

Swift said that while writing with Antonoff she began using what the two call a “gremlin voice.” “When we would be writing and you would send me an instrumental track,” she said to Antonoff, with a laugh. “I’d send you back me singing over it. And at the end of it I would always find myself going [transitions to creepy, crackly voice] ‘I hope you like it.'” It apparently became a thing between the two. They even made gremlin memes.

So while spending your entire Monday (and likely all of next week) listening to “1989” non-stop, remember the inspiration behind Swift and Antonoff’s songs. Also, don’t get this discovery confused with Swift’s other gremlin connection — the dog parody video of “Shake It Off” starring a rescue pit bull named Gremlin.

For more head to MTV.