BELFAST — Beware cheese cheats.

At the sixth annual U.S. National Cheese Rolling Championship this year, for the first time, there will be referees.

There will also be even more cheese.

The annual roll is part of the Maine Celtic Celebration, borrowed from the storied Gloucestershire cheese rolls in England, a more rough and tumble event — emphasis on the word “tumble” — and not without a bit of controversy.

In Gloucestershire, participants chase cheese down a long, steep, ragged hill. Here, it’s chased down a 100-yard slope known as the Belfast Common.

Here in Belfast, the cheese is real.

There — the horror — it’s not.

“They have been forced to use fake cheese, plastic,” Maine Celtic Celebration spokeswoman Claudia Luchetti said. “And there’s a big problem because it’s too light, and the people actually were getting out ahead of the cheese. But in general, it’s people chasing the cheese with us, or at least keeping up with the cheese.”

But maybe we’re getting ahead of ourselves. Or the cheese.

Cheese rolling is a straightforward enterprise, in general. Races are broken up by age, for men and for women. Too many entrants trigger a run-off up the hill for the nine open spots.

Participants then line up at the top of the hill, two or three feet apart from each other. The cheese master runs a few steps and bowls a 3-pound wheel of creamy cheddar. Then it’s game on. He or she who catches it first wins.

It gets competitive — fast.

“Everybody dashes down after,” said Luchetti. “There’s supposedly no wrestling over it after somebody has grabbed it, but that’s a little hard to enforce.”

Enter two newly added referees, “to make sure the person who actually gets the cheese first ends up with the cheese, especially in among the younger boys,” she said.

Hay bales line the bottom of the common to keep people from pitching into the road in pursuit of the cheese. And that’s worked. Mostly.

“We did have a couple of people spill over last year into the crowd,” Luchetti said.

Traditionally, the U.S. National Cheese Rolling Championship has been an eight-heat, eight-cheese event.

This year, organizers are turning it to 10.

Luchetti said that’s mainly to divide adult racers, who had been lumped together in an 18-plus age category. It’s now, tentatively, ages 19 to 24 and 25-plus.

The event begins at 1:30 p.m. on July 21. No need to sign up in advance — just show up nice and Limburger.

Dan Greeley will be there to defend his title. He’s the reigning men’s cheese champ from 2012, 2011 and 2008.

“Contrary to what people ask me, I do not go and chase stuff down that hill in preparation,” said Greeley, 46, of Belfast.

He plays soccer, bikes and keeps himself in good shape. Signing up for the first year was a given.

“I like competition and the idea of winning a roll of cheese — that sounded good to me,” Greeley said. “Mostly, what I like is the moment — standing on the top of that hill, waiting for the cheese to be rolled, a lot of friends around because it’s my hometown. That’s pretty exciting.”

He’s walked away each year with only bumps and bruises. Luchetti wasn’t aware of any serious roll-related injuries. The original Gloucestershire event has come under scrutiny for being too dangerous. Video shows people flipping and flopping down the hill, some bloody, but nearly all smiling at the bottom. They switched to fake cheese, hoping to slow people down.

In Belfast, it’s all real. Though this year, it’s moldy.

The State of Maine Cheese Company, the official cheese roll supplier, has in years past aged the cheddar for a nice, hard rind.

“This year, they’re wrapping the cheese in a cheese cloth,” said Luchetti. “It will get kind of that moldy surface on the outside of the cheesecloth, which will turn green. I’m wondering whether you’ll be able to see the cheese (in the grass) this year. That’s going to be a new twist.”