WhatsApp is about to give up to five million long-standing users the boot as it clamps down on the use of old phones.

The messaging app is ending support for a number of wildly popular devices just weeks after turning seven yeaars old.

In a statement, it called on people to buy new gizmos if they want to continue tagging along on its "amazing journey".

"This was a tough decision for us to make, but the right one in order to give people better ways to keep in touch with friends, family, and loved ones using WhatsApp," the firm annnounced.

These devices will no longer able to run WhatsApp:

• BlackBerry, including BlackBerry 10
• Nokia S40
• Nokia Symbian S60
• Android 2.1 and Android 2.2
• Windows Phone 7.1