Back in January, Skype announced it was testing end-to-end encrypted chat conversations, secured using Signal Protocol by Open Whisper Systems. Now, the feature is available for all users on Skype iOS, Android, Linux, Mac, and Windows Desktop.

To initiate a Private Conversation, select “New Private Conversation” from the compose menu or the recipient’s profile. The recipient will then receive an invite, and all calls and messages that transpire within that conversation will be encrypted end-to-end until it is terminated. There’s a bit of a limitation, however: users can only participate in one private conversation per device at a time. The private conversation can be switched to another device, but anything sent and received will be tied to whatever device is currently being used.

Previously, Skype did offer some form of encryption, but end-to-end encryption is more secure since the contents of messages can only be read by the sender and recipient. It joins the ranks of other chat platforms that offer end-to-end encryption, including Apple’s iMessage and Facebook’s Messenger, which also offers the feature as an opt-in.