Bunbury Primary School, south of Perth, has declared cartwheels and handstands too dangerous.
"This is not about stopping kids from taking risks and having fun," principal Shane Dougherty told Seven News.
"But attempting things like flips or handstands on bitumen and sloping grassed areas without learning how to do it properly is never a good idea."
One of Dr Duncan's specialty areas of research is risky play, and he says it's essential kids learn what they can and can't do the hard way.
"When you're a kid you've got to have the odd accident and learn those things don't work. Banning handstands is ridiculous, really," he told The AM Show on Monday.
"We're in a bit of a culture where we avoid risk at all costs, and we don't look at the benefits at all."
He says the "culture of fear" began in the 1990s, but many parents don't even realise they're contributing to it.
"We know now from the surveys we've done that most parents do actually believe kids should have some risk - 80 percent - but it's the minority that let them do it."
Bunbury is not the first school that's let the fun police run riot. A quick internet search brings up numerous cases over the last decade, mostly in Australia and the UK.
And don't get us started on bullrush.
"This will be the first generation of kids that can unlock an iPad before they can walk," says Dr Duncan.