We are mere days from the long-awaited Back to the Future Day, but guess what: The future is here, and it does not allow hoverboards. Not in the United Kingdom, anyway.

London’s Metropolitan Police, sent out a tweet yesterday informing residents and travelers that riding the boards in public is illegal. The group, then, followed that reminder with a link to the Crown Prosecution Service's full FAQ on so-called “self-balancing scooters.”

These modes of transportation are considered vehicles and require licensing and registration. Easy enough, right? Well, not exactly. Hoverboards, Segways/Swegways, and similar devices don’t meet road requirements, meaning trying to fulfill that requirement will likely lead to a dead end. Those who have been cruising the pavement are committing a violation under section 72 of the Highway Act 1835 or (in Scotland) section 129(5) of the Roads Act 1984. The laws also apply to sidewalks—which means if you’re going to cruise, stay on your own property.

No one has been arrested for unlawful hoverboarding as of yet, but riders of other self-balancing scooters have had the law laid down on their self-propelled merriment.

[h/t Mashable]