Justin Timberlake has “severely bruised” vocal cords, he announced to fans in an Instagram post Wednesday afternoon, explaining why he was calling off a Madison Square Garden concert at the last minute.

“Hey guys, I’m sorry to announce I have to postpone the show at MSG tonight on doctor’s orders. My vocal cords are severely bruised. I’m gonna make this up to you and the new show will be on my birthday, January 31. More info to come. Again, I’m so sorry to do this, but excited to see you soon. Love, J”

He’d successfully sung his way through a gig at the venue two nights earlier, doing his usual two-hour, 26-song set, according to published accounts. Ironically, Monday’s show was a make-up gig itself, following the postponement of a March concert scheduled for Madison Square Garden that Timberlake had put off due to a Nor’Easter.

His spokesperson could not immediately be reached for comment on whether other dates may be affected on the tour, the next dates of which are scheduled for Sunday in Buffalo and Monday and Tuesday in Tacoma, Washington. The tour was originally supposed to wrap up on January 29 in Denver, before the addition of this MSG makeup date two days later gave it a new end date.