WhatsApp, the messaging app with over 1 billion users and owned by Facebook, is set to make its biggest update ever with the addition of a video calling option as it seeks to compete with Microsoft-owned Skype.

According to those enrolled in WhatsApp's testing program, which gives users early access to new features not yet ready for the general public, a new version of the app that included an option for video calling was pushed out over the weekend for Android users.

When users tried to call a contact they were given the option of a voice call (a feature introduced in January 2015) and a video call. While the feature was inactive for some users, others were able to make video calls, according to a report by Fone Arena.

WhatsApp was not immediately available for a comment on the possibility of releasing a video call feature for its popular app, but this is not the first time details of the new option have leaked. Back in December, leaked screenshots of the iOS version of the app were published by a German website Macerkopf while earlier this month Android Police reported that users who help translate WhatsApp into other languages have received new strings to translate, including “Video call,” and “Video calling is unavailable at this time.”

WhatsApp, which recently rolled out end-to-end encryption for all its users by default, famously has a very small team of engineers (Wired reported it had just 50 engineers in September 2015) meaning that features that have been available on other messaging services for some time, take a lot of time to come to WhatsApp.

The company recently launched standalone desktop apps for Windows and Mac OS X, meaning it is now available on virtually all devices from smartphones and tablets to desktops and laptops. Adding video calling to its desktop app will bring it into direct competition with Skype as it seeks to become the world’s most dominant messaging app.