PepsiCo will start selling Diet Pepsi without aspartame later this year after a consumer backlash against the artificial sweetener crushed sales.

The company will begin to replace aspartame with a blend of sucralose and acesulfame potassium in Diet Pepsi, Caffeine Free Diet Pepsi and Wild Cherry Diet Pepsi sold in the U.S. in August. Diet Pepsi’s sales declined 5.2 percent last year, according to Beverage-Digest. Sales of Coca-Cola’s Diet Coke, which also uses aspartame, dropped 6.6 percent.

PepsiCo is getting the jump on Diet Coke, the country’s No. 1 sugar-free soda, in removing the controversial sweetener. Consumers have been backing away from both brands in recent years, fearful that the lab-created sweetener may cause cancer. The U.S. Food and Drug Administration has said there is no proof of a health risk from aspartame.

“Diet cola drinkers in the U.S. told us they wanted aspartame-free Diet Pepsi and we’re delivering,” said Seth Kaufman, senior vice president of Pepsi and the company’s flavors drinks in North America.”We recognize that consumer demand is evolving.”