How to set Shutter as default screenshoter in Ubuntu 14.04

I'm using standard Ubuntu 14.04 with Unity, how come I cannot set Shutter as default screenshoter anymore? I tried everything I knew, I purged it and reinstalled it completely, set it in Compiz Settings Manager shutter -f and shutter -a ticked the Gnome Compatibility Plugin, even rebooted the system completely still it doesn't react when I press PrintScreen instead basic screenshoter takes a screenshot. Is there something else has changed with compatibility?

Go to keyboard under system settings, and create a new custom shortcut.

Once created, click on disabled, and once it changes to new accelerator, just press PrintScreen button, and you're all set.