How to disable clamshell mode behaviour? Force machine lock on lid close

90% of the time I work with my macbook connected to a screen.

I want my macbook to go to preferably lock, but will settle for sleep, when I close it.

I don't care if it is doing anything, if I close the lid, I want the entire machine to lock/sleep.

This does not seem to be possible from what I can tell but I am hoping that you can prove me wrong.

Thanks for any suggestions that you can offer.

Sadly I don't think you can invoke this behavior and this is not the solution you are asking for, though as I imagine you are using a keyboard (apple?) you could always use the hotkeys to lock your laptop and screen.

• Option–Command–Power / Option–Command–Media Eject: Put Mac to sleep
• Control–Shift–Power / Control–Shift–Media Eject : Put display(s) to sleep

https://support.apple.com/en-us/HT201236