OKLAHOMA CITY — The Oklahoma Supreme Court has overturned a lower court ruling that hundreds of restaurants in the state overcharged customers for mixed drinks.

Lawsuits filed in 2011 by Tom Erbar and John Truel alleged restaurants overcharged by adding a 13.5 percent liquor tax to advertised price of mixed drinks. The lawsuits were combined and contended the tax should have been included in the advertised price of the drink.

Tuesday’s ruling overturns an earlier ruling by a Canadian County judge in the lawsuit.

Supreme Court Justice James Winchester wrote in the ruling that the law in question is a tax law, not a consumer protection law.

Winchester also notes that the Legislature amended the law in question in 2013.