The two US pop stars fell out all the way back in 2013 over a row about backing dancers.
The enemies have been taking shots – some thinly veiled, others less so (hello, Bad Blood!) – at each other ever since.
But on Tuesday, Katy shared a picture of a plate of cookies with the words ‘Peace at last’ scrawled on the plate in red icing.
Katy tagged the location ‘let’s be friends’ and added the caption, ‘Feels good @Taylorswift’ and added a heart emoji.
The post sparked a flurry of comments from fans who are hoping it signals a possible collaboration.
‘WE WANT A COLLAB BREAK THE INTERNET,’ wrote one fan, while another shared, DO I SMELL A COLLAB?’
It’s not the first time Taylor and Katy have tried to make peace.
Last May, Taylor sent an olive branch (literally) to Katy, but the Love Story singer was reportedly left furious after the Roar star shared evidence of the gesture with her millions of fans as it was supposed to be private.
In 2017, Katy spoke publicly about the pair’s feud, telling NME: ‘No one has asked me my side of the story, and there are three sides of every story: one, two and the truth.’
She went on: ‘I wish I could turn the other cheek every single time, but I’m also not a pushover, you know?
‘Especially when someone tries to assassinate my character with little girls. That’s so messed up!’