Twitter Circles might not be around much longer.

In a late Friday tweet, Elon Musk announced that Twitter will be "deprecating Circles in favor of improved Communities & DM group chat.”

Musk didn’t provide any additional information, so it’s a bit unclear what he means by “deprecate.” The company could be ending technical support for the feature or it could be removing it entirely from the platform.

Twitter introduced Circles last August as a way for Twitter users to post tweets that are only accessible to a select few followers, similar to Instagram's Close Friends feature.

The feature had a security breach in April, which caused some of those tweets to be visible outside of private Circles. Twitter blamed a “security incident” for the bug and said it was “committed to protecting the privacy of the people who use our service, and we understand the risks that an incident like this can introduce and we deeply regret this happened.”

Shortly following Musk’s tweet, “Circles” was trending on Twitter, with many current Circles users both mourning the loss of the feature and asking what might happen to tweets that have already been posted in Circles, a detail that is currently unclear.

Twitter’s Communities feature has been around since 2021 and offers a similar yet different experience, allowing users to connect with others on the platform with similar interests, like dogs or astrology.

Unlike Circles, tweets posted in Twitter Communities are visible to the wider Twitter audience. But those who aren’t part of the Community can't engage with tweets or participate in Community discussions. It’s possible that Musk’s reference to “improved Communities” could mean adding the ability to create private Communities comparable to a Twitter Circle.

Musk’s announcement also comes just days after the launch of Meta’s new app Threads, which offers a similar look and experience to Twitter.