YouTube is engaging in some year-end cleanup that could result in channels seeing a decrease in their subscriber counts.

The video giant on Tuesday warned creators that they may see a decrease in subscriber counts on Dec. 3 as it removes “closed accounts” from the overall tallies.

YouTube didn’t say how big a drop in subscriber numbers creators might see, but said that sometimes “due to technical or process reasons, we may need to remove more than the usual amount of closed accounts on one day.”

In a notice on its help site, YouTube says, “We regularly validate if accounts on YouTube are real and legitimate, which is part of an ongoing process to make sure that our site metrics are free of spam, abuse, and closed accounts to keep YouTube a fair place for everyone.” In December 2018, for example, YouTube issued a similar warning to creators on the eve of a broad purge of spam accounts.

According to YouTube, closed accounts are those that were either shut down by the user or terminated by YouTube or Google for policy violations.

YouTube said that if creators’ channels have had closed accounts removed from their subscriber count, that will be reflected in the YouTube Studio’s YouTube Analytics dashboard for Dec. 3-4 within the next 48 hours. YouTube noted that since the accounts are already inactive, “removing them from your subscriber count shouldn’t have an impact on watch time.”