On Wednesday morning, many marketers, journalists and news junkies were met with a paywall they have been dreading: X, formerly known as Twitter, started charging users to access TweetDeck.

TweetDeck, now called X Pro, allows users to view and customize multiple feeds that update in real time. The platform was acquired by Twitter in 2011 after it became one of the most popular ways for people to access the site.

The service has historically been free to use, but X announced in a post in July that it would become a subscriber-only feature. Starting Wednesday, users who want access to X Pro will have to pay for X Premium, the service introduced by the site’s owner, Elon Musk, as a way to generate additional revenue for the company. The subscription costs users $84 a year.

People who purchase X Premium will also receive a blue checkmark on their account, in addition to prioritized rankings in replies and search, access to longer posts and fewer ads, among other features. The service, formerly called Twitter Blue, got off to a rocky start in November when it was pulled after users created accounts posing as popular brands and celebrities. Twitter Blue relaunched again in December, though impersonation problems persisted.

Musk, who is also the CEO of Tesla and SpaceX, acquired Twitter late last year for $44 billion. Employees and users felt his impact immediately, as he enacted steep job cuts and introduced a number of major new features and policy changes on the platform.

Most recently, the company began to carry out a sweeping rebrand, which Musk announced in July. Twitter retired its famous blue and white bird logo and transformed into X. Changes to the names of Twitter’s services such as TweetDeck quickly followed.