Twitter has started building an encrypted direct messaging feature in its Android app, according to a computer science student who dug through the code. Jane Manchun Wong looked through Twitter’s Android app code and saw the feature.

Other apps like WhatsApp, Telegram, and Signal already provide users with encrypted means of communicating. If Twitter added secret conversations, its direct messages could serve as a convenient alternative to secure, off-platform rivals.

Since the feature was found in the app’s unreleased code, it’s unknown when, if ever, the feature will actually go live. Reports of Twitter working on encrypted direct messages surfaced back in 2013, but the company dropped the feature without an explanation in early 2014. It declined to comment on why back then, but signs pointed to its overwhelming to-do list.