An Illinois man has filed suit against Southwest Airlines, claiming breach of contract, after the discount flyer said in August 2010 it would stop honoring coupons for free alcoholic beverages that had no expiration dates.

Adam Levitt said for years he and passengers like him bought tickets through Southwest’s higher priced Business Select program, and the airline awarded those customers with coupons for free drinks, which would otherwise cost $5 each. The coupons had no expiration date.

But on Aug. 1, 2010, the company changed its policy, making drink coupons only valid on travel dates printed on the coupon. According to a blog post by Southwest’s vice president of cabin services, the airline made the policy change in an attempt to boost its bottom-line.

Levitt said in his suit, filed Nov. 16 in Chicago, that the policy change was a breach of contract. “Southwest decided that it would make more money—improve its ‘bottom-line’—by choosing not to honor the coupons that consumers had already paid and bargained for,” the complaint said.

Levitt is seeking class-action status on behalf of all Southwest customers in the U.S. with unredeemed drink coupons. The suit also seeks compensatory damages and other remedies.