Sir Elton John canceled his scheduled tour date in Indianapolis on Saturday.

In an Instagram post, John said that he was “extremely unwell” and promised to reschedule the concert early next year.

“To my dear fans in Indianapolis, it is with the heaviest heart that I'm forced to deliver the news that I am extremely unwell and therefore unable to perform at @bankerslifefieldhouse tonight,” John captioned a photo of himself performing.

“I absolutely hate to let my fans down, but I owe it to you to put on the best #EltonFarewll Tour show possible and unfortunately that's simply not possible. The date will be rearranged for March 26th 2020, and I promise I will deliver the show you deserve.”

“Thank you so much for your support and understanding. xx,” he added.

(Related: Elton John: George Michael was “uncomfortable” being gay.)

John, whose memoir Me: Elton John Official Autobiography arrived this month, is currently on tour for the last time. His “Farewell Yellow Brick Road” tour includes more than 300 shows and ends in 2021.