X is raising prices for its top-tier subscription service, Premium+, by 37.5% to $22 a month, marking the largest price increase since Elon Musk bought the platform in 2022.

The price hike will first affect U.S. users, going up from $16, effective December 21, according to a statement. Annual subscriptions have also climbed to $229 from $168.

X said it was “adjusting” the prices to support the experience it offers. Existing subscribers will be grandfathered into current rates until January 20.

International markets face similar increases, with prices for people in the European Union rising to €21 from €16 monthly. Canada will see Premium+ rates climb to $29 from $20.

Some markets are more impacted than most. X Premium+, which completely removes ads and adds other features, will cost users in Nigeria ₦34,000 monthly, up from ₦7,300. Users in Turkey, similarly, will have to pay ₺770 for the service, up from ₺300 currently.

The platform’s basic subscription tier will still cost $3 a month.