Textbook publishers will have to disclose their book prices and edition changes to college professors in Washington State if the governor signs into law a bill the state’s Senate passed unanimously this week.

Students lobbied for the bill though the State Public Interest Research Groups, according to the Seattle Post-Intelligencer. The logic behind the measure is that professors will be less likely to assign a costly textbook if they are aware of its price and know that the publisher issues frequent new editions that differ little from old ones. The Seattle Times said Gov. Christine Gregoire, a Democrat, was expected to sign the bill.

Several states — including Arkansas, Illinois, and Minnesota — are considering other measures to ease the burden on students of expensive textbooks. This spring the U.S. Department of Education’s Advisory Committee on Student Financial Assistance plans to present a comprehensive report on textbook costs to Congress. —Sara Lipka