What is the IL state employment law regarding overtime pay

Illinois OVERTIME law clarification for hourly employees: My husband works as a mechanic and is an hourly paid employee. He works for a marina and this is an extremely busy time of the year with winterizing and when he usually makes his winter financial "cushion" with all the overtime pay.
Just this week, however, his employer announced that no one will be paid for more than 40 hours per week. They stated that employees can "opt to work more than 40 hours per week" and they would offer to do one of the following to "compensate them":
1-bank the extra hours and in the future, pay them but at STRAIGHT/REGULAR HOURLY PAY
2-let them bank extra vacation hours but again at STRAIGHT/REGULAR HOURS and not 1.5 HOURS

Is this legal in Illinois? I thought "comping" overtime pay for non-government employees is illegal? And even if it's not, shouldn't they be required to compensate whether with pay or extra vacation hours at time and a half? - Is this your question? Add additional information