For eight months, iPhone users with AT&T unlimited data plans were unable to make FaceTime calls over cellular, but that's about to change.

The carrier just announced on Tuesday, May 21, that it plans to allow software and smartphone makers to enable cellular video calling on apps (such as Apple's FaceTime feature) that come pre-installed on devices for unlimited-data users.

AT&T will start enabling cellular video calls to pre-installed apps by mid-June and will continue the process throughout the rest of the year. It remains unclear at this point when exactly each app will get the green light.

"For video chat apps that come pre-loaded on devices, we currently give all iOS and device makers the ability for those apps to work over cellular for our customers who are on Mobile Share and Tiered plans," AT&T explains in a statement to The Verge. "Apple, Samsung and BlackBerry have chosen to enable this for their pre-loaded video chat apps. And by mid-June, we'll have enabled those apps over cellular for our unlimited plan customers who have LTE devices from those manufacturers."

"Throughout the second half of this year, we plan to enable pre-loaded video chat apps over cellular for all our customers, regardless of data plan or device; that work is expected to be complete by year end. Today, all of our customers can use any mobile video chat app that they download from the Internet, such as Skype," adds the statement.

AT&T was the only network to block its unlimited-data users from accessing the video calling feature on its cellular network, and got plenty of criticism over the issue. Sprint and Verizon allowed the feature for their customers ever since Apple released it for iPhone users back in September, but AT&T was very strict about it.

The carrier only allowed users on its shared data plans to access such apps and features at first, but it gradually started to extend this courtesy to other users as well. Only users who are grandfathered into AT&T's services with unlimited data plans are currently left out of the picture.