Wednesday, the Illinois Labor Relations Board said the district retaliated against union employees last year, when it chose to outsource its drivers.
Last spring, Unit Five hired private busing company First Student to fix what it called a driver shortage.
Prior to the decision, AFSCME Union employees drove the routes.
Members filed an unfair practice complaint against the district stating it didn't bargain with them in good faith when it opted to outsource.
Wednesday's decision by an administrative law judge is calling on Unit Five to negotiate a fair contract with union workers.
"We're running the best we've ever run in transportation right now," said Superintendent Gary Niehaus. "Things are going well. We're happy with our contract. We think we made the right decision."
"It's been a long time coming," said AFSCME Council 31 Staff Representative Renee Nestler. Members have been through a lot. This is a complicated situation. The decision is complex and a lot to digest. We will have to take the time to evaluate the legalities and precede forward."
Unit Five will file objections to the Illinois Educational Labor Relations Board and could also take the matter to the 4th District Appellate Court.