(Reuters) - Oklahoma’s Senate on Wednesday approved legislation for the first major tax increase in a quarter century to help fund pay raises for teachers and avert a strike.

Low teacher pay in the United States came into focus earlier this month when educators in West Virginia, whose pay is slightly higher than in Oklahoma, held a nine-day strike that ended after they received a 5 percent pay rise.

The Oklahoma measure, which will raise about $450 million to fund increased pay for teachers, school staff and state workers, had already passed the state House and Oklahoma Governor Mary Fallin said on Wednesday she would sign it into law.

But the money may not be enough to satisfy the demands of Oklahoma’s teachers, who rank among the worst paid in the United States and had been planning a strike for next week.

“There is still work to do to get this legislature to invest more in our classrooms,” Alicia Priest, president of the Oklahoma Education Association (OEA), the state’s largest teachers union, said in a Facebook post after the Senate vote.

“That work will continue Monday when educators descend on the Capitol”, Priest said.

The tax hikes on cigarettes, fuel, lodging and oil and gas production will fund a $6,100, or 16 percent, pay raise on average for Oklahoma teachers, Fallin said in a statement.

The OEA, which has about 40,000 members, has said it is seeking a $10,000 pay increase over three years for teachers and a $5,000 raise for support personnel.

According to National Education Association estimates for 2016, Oklahoma ranked 48th, followed by Mississippi at 49 and South Dakota at 50, in terms of average U.S. classroom teacher salary.

Oklahoma secondary school teachers had an annual mean wage of $42,460 as of May 2016, according to the U.S. Bureau of Labor Statistics.

For the past few years, Oklahoma has battled budget deficits stemming from the 2014 collapse in oil prices that hit its large energy industry and slammed state revenue.