All Tvvins are playing the Saturday night of Longitude.
The duo, made up of Conor Adams and Lar Kaye, made the exclusive announcement on Plan B today.
Their first album, llVV, peaked at number two in the Irish album chart but the lads told Sarina Bellissimo that they were a little "disappointed" it never hit number one.
However, they're grateful for the success, "the fact that it was in the charts at all ... was a buzz".
Conor and Lar also chatted about the not-so-glamorous tour life, how they met James Vincent McMorrow through Twitter and what they've planned for the future.
Listen back to it here:
Plan B airs on Spin1038 every Saturday from 1pm and for more festival tips.