Because I live in a small household, and use my computers for pretty boring stuff, I’m not all that paranoid about who looks at my laptop. But I do understand the desire to know if anyone has been looking at your MacBook, whether it be nosy co-workers or family members.

This simple trick, shared on Reddit by user Moosehadley, is a clever way to do just that, by allowing you to search for the record created every time your MacBook is opened and woken up from sleep mode. It doesn’t even require any scary Terminal work or file patching.

To take a look at the log, go to Utilities>Console on your Mac. This is an app that records crashes and other diagnostic information about your computer. Once you’re there, click on ‘kernel.log’ in the left column.

Then click in the search field at the top and type ‘Wake reason: EC.LidOpen’. Hit enter and be rewarded with a list of events that show you exactly when the lid was opened. Then proceed to run into your little brother’s room and give him a noogie for using your computer.