Popular 90s girlband All Saints will reunite to perform classic hits "Pure Shores" and "Never Ever" as special guests on Backstreet Boys' upcoming UK and Ireland tour.
After previously squashing comeback rumours, All Saints have promised to sing their biggest songs, with no "new material" to distract from what their fans want to hear.
US boyband Backstreet Boys will perform five headline dates next year in support of their new album In A World Like This.
Shows have been scheduled for Birmingham, Dublin, Glasgow, London and Manchester in March and April next year.
"We are really looking forward to performing together as special guests," All Saints said. "The Backstreet Boys are a great band, so it's an honour."
Backstreet Boys co-headlined with fellow American boyband New Kids On The Block for their last UK tour.
"We had a fantastic time - the reaction was out of this world. We can't wait to come back and blow you away with our own full headline show," they said.
"We're really excited for our UK fans to see us again as a five-piece. The original Backstreet's back!"