Facebook has quietly removed the ability to sign up for Messenger without a Facebook account, the company confirmed to VentureBeat this afternoon. Previously, new users using the Messenger or Messenger Lite app could opt to use their phone number in lieu of an account.

“If you’re new to Messenger, you’ll notice that you need a Facebook account to chat with friends and close connections,” a spokesperson said via email. “We found that the vast majority of people who use Messenger already log in through Facebook and we want to simplify the process. If you already use Messenger without a Facebook account, no need to do anything.”

Some Messenger users without Facebook accounts report that the transition hasn’t gone smoothly. Perhaps owing to a bug, they say they’ve encountered an error message indicating that their account has been restricted.

Facebook rolled out the ability to sign up for Messenger sans account in June 2015, first for users in the U.S., Canada, Peru, and Venezuela. In addition to phone numbers, photos and names were accepted as forms of login identification.

The change might anticipate the forthcoming unification of Facebook’s various messaging properties, which include WhatsApp and Instagram as well as Messenger. The New York Times reported in January that the technical infrastructure underlying all three services will be integrated, potentially redefining how over three billion people around the world communicate. (WhatsApp has more than 1.5 billion active monthly users, while Messenger and Instagram have over 1.3 billion and 1 billion, respectively.)

In an announcement earlier this year, CEO Mark Zuckerberg laid out Facebook’s plan for a shift toward end-to-end encrypted, ephemeral messaging, in accordance with the social network’s new interoperability principle. “People should be able to use any of our apps to reach their friends, and they should be able to communicate across networks easily and securely,” he wrote in a blog post. “We plan to start by making it possible for you to send messages to your contacts using any of our services, and then to extend that interoperability to SMS too.”

Doubling down on messaging could prove to be a lucrative decision in the long run. By recruiting businesses and brands to message users about promotions and by decreasing the friction of in-message purchases, Facebook stands to make well over the roughly $55 per user it paid to acquire WhatsApp in 2014.

“Today we already see that private messaging, ephemeral stories, and small groups are by far the fastest growing areas of online communication,” Zuckerberg continued in the March post. “As I think about the future of the internet, I believe a privacy-focused communications platform will become even more important than today’s open platforms.”