LAS VEGAS (AP) — An arbitrator has sided with the teachers' union in a dispute with the Clark County School District, awarding retroactive pay for teachers who received graduate degrees.

The Las Vegas Review-Journal reports the district and the Clark County Education Association had agreed to a deal in 2016 to overhaul the salary schedule for teachers.

The agreement provided a salary step increase to all licensed professionals and a more than 3 percent cost-of-living raise for the 2016-2017 school year.

The district did not give the increases to teachers who earned an advanced academic degree in the 2015-16 school year because of a dispute over the interpretation of the agreement.

District officials say they're working to determine the cost of the arbitrator's decision.