WP810 Disable key presses while proximity sensor is active



I would like an option to disable key presses on the WP810 handset during an active call, so basically when the proximity sensor is active. The reasoning behind that is to prevent unwanted key presses (or in my case a hang up) when you put the handset between your head and your shoulder.

If this is somehow possible right now, please let me know. I couldn’t find any setting.