Like all good internet gags, the #HardHatChallenge has come from nowhere to become the single most entertaining thing online right now.
While it's not clear where it originated from, the challenge seems to have started popping up around April last year.
In the last couple of weeks, though, it's certainly picked up steam - and it's taking tradies out left, right and centre.
The whole thing sounds simple enough: your hard hat starts on the ground, you flick it with your foot and it lands on your head.
Except it's supposed to land the right way up on your head, not knock you out in the process.
If you haven't already, we'd recommend taking a trip through the thousands of videos on Instagram under the #HardHatChallenge hashtag.
Or you could just watch this fail compilation.
Apparently it is do-able, though; this guy managed it with an extremely precise technique that involves paying close to attention to where exactly you position the shovel in the cap.