Raleigh, N.C. — Brasa Brazilian Steakhouse has agreed to pay more than $68,000 in back wages to 18 workers after a federal investigation determined the restaurant violated labor laws by not giving the workers overtime.

An investigation by the U.S. Department of Labor’s Wage and Hour Division found the Raleigh restaurant paid its kitchen staff straight time, rather than time and a half, for hours worked beyond 40 in a week. The employer also incorrectly calculated overtime for tipped employees.

Investigators said the employer also failed to pay some workers for all their hours, which meant they earned less than minimum wage.

The Fair Labor Standards Act sets the minimum wage at $7.25 per hour. Tips combined with direct wages must be at least minimum wage, or the employer has to make up the difference, according to the law.

“Workers in the restaurant industry are among the most vulnerable in this country, and the Labor Department will not tolerate their exploitation,” Richard Blaylock, director of the division’s Raleigh office, said in a statement. “This case should serve as a notice to other employers who may not be paying their employees in accordance with federal law.”

The department has a smartphone application, available in English and Spanish, to help employees track hours and determine wages they are owed.