Tesla a few months ago rolled out a software update with a feature it calls Smart Summon. As the name suggests, the feature allows Tesla owners to beckon their car and have it drive itself to wherever they happen to be. Imagine, for instance, leaving a supermarket in the pouring rain and having your car meet you at the exit. The original incarnation of Summon was introduced in 2016 but the underlying functionality is essentially the same.

“It’s the perfect feature to use if you have an overflowing shopping cart, are dealing with a fussy child, or simply don’t want to walk to your car through the rain,” Tesla said of the feature. “Customers who have had early access to Smart Summon have told us that it adds both convenience to their trips and provides them with a unique moment of delight when their car picks them up to begin their journey.”

Now that’s all well and good, but one use-case scenario Tesla forgot to mention involves scaring the bejeezus out of your good-natured grandma.

Recently, a video making the rounds on Reddit showed someone doing just that with the first incarnation of the feature. It may seem cruel at first glance, but the car is moving so slowly that it’s really more comical than anything.

The video itself is an oldie but a goodie, and if you haven’t seen it before you’re in for a treat.

And for good measure, and because people seemingly enjoy giving their grandmother’s heart attacks, this video of another grandma being blown away by a Tesla on Autopilot is worth sharing.