Next time you go for a Big Mac and Coke you might want to think twice before asking for ice in your drink.
At least that's the advice of one former McDonald's employee, who has given his top tips for ordering a meal from the fast food giant.
Speaking to the Sun, the mystery employee - who worked at a McDonald's in Essex - says customers should never get ice with their drinks, for a very good reason.
He said: "I would never get anything with ice in it. It's not the water that is used to make the ice.
"It is the machine. It just isn't cleaned as often as it should be."
However, it's not all bad news, the anonymous crew member also revealed a few tips for the next time you go to the golden arches.
The former employee says always ask for 'no salt' to get the perfect fries. Credit: McDonald's
The first piece of advice he claims will make sure you get the perfect portion of chips every time.
He told the paper that if you want to make sure you get the freshest fries possible then ask for no salt with your order.
"Order your chips without any salt because then we have to make a fresh batch of fries," he said.
"We also have to clean out the tray that the fries are stored in to make sure no salt gets on them."
He also said try and make sure you get to your local Maccies just after peak times, because that is when menus are changed over.
The ex-crew members used to work at a restaurant in Essex. Credit: McDonald's
The employee said: "The peak times are 8am-10am, 12pm-2pm, and 5pm-7pm."
Over the years there have been many rumours about what exactly is in a McDonald's milkshake, how clean they really are, and why they are so thick.
Well, according to this ex-employee it's not their hygiene that's in question - he says they're just made from exactly the same stuff as their ice creams and he would never order one.
He said: "It's a white liquid that comes in a sealed bag that we pour into the machine.
"I just don't see the point in paying for one or the other when they are literally made from the same thing."
A McDonald's spokesman told the Sun: "We encourage all of our crew to speak up if they have any concerns, offering formal and informal channels for issues to be raised."
Featured Image Credit: McDonald's/PA