WhatsApp is the most popular IM messaging service on mobiles that people use in order to stay in touch with their friends and family. Over the period of time, WhatsApp became so popular that eventually it was acquired by social media giant Facebook. However, competitors have always been ahead in the game in terms of features. Nevertheless, one particular feature that WhatsApp still lacks is voice calling.

WhatsApp said last February that it was working on bringing voice calling feature, but that’s about it. Apart from a few hints here and there, no major mention of WhatsApp voice calling feature was spotted anywhere until recently. A recently leaked screenshot suggests that WhatsApp is indeed testing the voice calling feature.

The screenshot was taken with a device running Android 5.0 Lollipop OS, suggesting that it couldn’t have been older than a few weeks. The leak includes a screenshot of separate window for call logs inside the contact profile, an incoming call and a call in progress.

WhatsApp CEO Jan Koum last October confirmed that the service would roll out video calling feature, but it was delayed because of few technical hurdles its developers were facing. He gave a timeline of Q1 2015 for the official release of WhatsApp voice calling feature.

As the year 2015 is approaching, this news gives glimpse into what WhatsApp’s voice calling feature may look like on an actual device. The screenshot, however, could not be verified as WhatsApp has not officially announced anything regarding voice calling feature. As of now, it remains to be seen when the feature may actually roll out on stable releases.