Minimum wage in Alberta is going up to $9.40 an hour on Sept. 1.

The 60 cent jump announced Wednesday by Employment and Immigration Minister Thomas Lukaszuk is the first increase since April 2009.

Minimum wage for workers who serve alcohol is set at the lower rate of $9.05 an hour because they earn tips.

"They vary from restaurant to restaurant but nonetheless when you combine minimum wage with gratuitites in those liquor-serving establishments, the combined income is significantly higher than that of a minimum wage," Lukaszuk said.

The province intends to keep the rate at $9.05 an hour until the general minimum wage increases to $10.05 an hour. Once that happens, there will always be a $1 an hour difference between the two rates.

Any future increases to the minimum wage will be set by a formula using the average weekly earnings in Alberta as well as the Consumer Price Index, Lukaszuk said.

If it is changed from one year to the next, it will always take effect on Sept. 1.

About 20,000 Alberta workers have jobs that pay minimum wage.