Costco just announced that all employees at its non-union stores will get a pay raise a day before employees at its 50 unionized stores are set to go on strike.

The top of scale workers will be at $30.20 an hour, while bottom of scale employees will begin at $20 an hour.

According to the memo, Costo will increase hourly pay for its top of the scale employees, or employees in senior positions, over the next three years. The pay will initially increase by $1 to $30.20 in the first year and an extra $1 each in the following two years.

An estimated 18,000 Costco employees are members of the International Brotherhood of Teamsters, and 85% of them voted to strike.

Costco Teamsters members voted to authorize a strike if negotiations on a new contract don't result in a new deal by Jan. 31.