NEW YORK (AP) — PepsiCo is putting aspartame back in some of its diet beverages less than a year after pulling the artificial sweetener as part of a marketing move over safety concerns.

The sweetener had been linked to cancer in lab mice and industry executives blamed the decline in sales on unfounded concerns people have about aspartame. The removal of the sweetener tested the theory that the sweetener was to blame for fleeing customers. But, the move seems to have been a misstep, with consumers dissatisfied over the change in flavor without the sweetener.

Pepsi MAX will be re-introduced to U.S. consumers this fall as Pepsi Zero Sugar and will contain aspartame. Diet Pepsi Classic Sweetener Blend will contain aspartame in its formula. But Diet Pepsi will continue to be sweetened without aspartame.