A number of YouTube channels are experiencing huge subscriber count losses, as the result of a glitch that occurred Wednesday afternoon.

The glitch was first reported by YouTube user BlackScreenTV, who theorized that it was caused by a counting error when subscribing and un-subscribing. We conducted our own tests, and found his theory to be correct.

Here’s an example: You find a channel that has 1,000 subscribers. If you subscribe, their count would be increased to 1,001 – normal, intended behavior. When you immediately unsubscribe, however, their count decreases by two, dropping to 999. The ending result is a net gain of -1 subscribers, as opposed to 0.

The glitch caused many top channels to seemingly lose thousands of subscribers on Wednesday afternoon, with several channels dropping into the negatives.

This bug does not affect real subscriptions, however, and channels aren’t losing any subscribers that didn’t explicitly click ‘unsubscribe’ – this glitch only affects the total subscriber count displayed.

UPDATE 5:20pm ET: YouTube confirmed that they are aware of the bug, and that subscribers aren’t actually being lost, with a tweet to Ethan Klein of H3h3productions:

@h3h3productions We're aware! No subs or data is lost, it's an issue w/ how the sub count # is being displayed. We're working to fix it. — Team YouTube (@TeamYouTube) February 8, 2017

UPDATE Thursday, Feb 9, 1:50pm ET: YouTube has confirmed that the glitch has been fixed, and subscriber counts across the board have returned to their normal values.

Sub counts are now fixed! We incorrectly showed a decrease of 2 instead of 1. No additional ppl were actually unsubbed. Sorry everyone! https://t.co/2v0XcsijMN — Team YouTube (@TeamYouTube) February 9, 2017

Check out the channels with the biggest drops in subscribers here.

Watch the live subscriber count of your favorite YouTube creators on the web here, and on Android here.