Skeleton in HOV lane
The California Highway Patrol shared a photo of a driver using the carpool lane with a Halloween prop. CHP

California police are reminding Halloween enthusiasts that carpool lane companions must have a heartbeat in a hilarious Facebook post.

The California Highway Patrol in San Jose shared a photo of a driver seemingly receiving a ticket for driving in the carpool lane with a terrifying mask and skeleton costume strapped to his passenger seat.

"While #spookyseason is upon us, it's important to remember that decorations being transported in the passenger seat do not qualify to meet carpool requirements. #californiahighwaypatrol #santaclaracounty #carpool #halloweendecor," the post read.

The post went viral, with hundreds of users chiming in on their experiences with the carpool lane.

"It's the oldest car-pool trick in the book. When I was a kid in the 1970s, I saw cars with dressed mannequins," User Donald Fong comments.

Several users defended the harmless prankster's action and chided the department for reprimanding him a ticket.

"They should have left that guy alone," Robert Blakemore wrote.

"It is a pretty stupid thing to pull over a person for having a Halloween toy in the passenger seat. People enjoy seeing that as they look over at the car. I believe the man just wanted to share a Halloween decoration and this is not right. They should have just told him to move the item from the front seat and let it go," he added in his comment.