Wal-Mart is introducing a new dress code for its employees, but they’re not calling it a uniform. And that’s got some Wal-Mart employees riled up.

The retailer says customers are having a hard time figuring out who works at the store, so it’s put in place a dress code. Employees have to wear black or khaki pants and a blue or white collared shirt.

Judith Conti of the National Employment Law Project, a nonprofit that advocates for low-wage workers, says employees are upset about this because they have to pay for the clothes.

“Wal-Mart employees are among the lowest paid in the entire country,” Conti says. “And Wal-Mart is asking them to buy new clothes to wear at work.”

Wal-Mart didn’t respond to an interview request, but it has said that most of the feedback about the dress code has been positive.

Reuel Schiller, a professor at UC Hastings Law School, said it’s significant that Wal-Mart isn’t calling this a uniform.

“There’s a legal difference between a uniform and a dress code,” says Schiller. If the cost of the uniform will actually pull your wages below minimum wage for the week that you bought it, then under federal law that’s illegal.  

Schiller said Wal-Mart skirts the issue — and passes on costs — by going with a dress code.