WhatsApp have confirmed the launch of a new feature which may upset some users.
The instant-messaging app has always used two green ticks - one to signify a sent message and one to alert the sender that the message has been received the other end.
The new feature will now turn both ticks blue when the recipient has read the message - meaning users will no longer be able to use the excuse that they didn't see the message.
WhatsApp will start rolling the feature out amongst all users and confirmed it is not optional - meaning it can't be turned off. Android users are already experiencing the update which will eventually be rolled out to all users.
Facebook acquired the app for $19bn in February. Facebook also own Instagram and previously made a failed bid for Snapchat.