Grocery store cake mixes by Duncan Hines, known for flavors like Classic Yellow, are being recalled due to a possible salmonella outbreak.

Conagra Brands, which owns Duncan Hines, is voluntarily recalling four varieties of their cake mixes: Classic White, Classic Yellow, Signature Confetti and Classic Butter Golden, the Food and Drug Administration said.

Though the FDA is investigating five instances of illness from salmonella, it has not confirmed if the cake mix is directly linked to the outbreak. But some of the people who got sick reported eating the cake mix before falling ill, and some even ate it raw.

Healthy people infected by salmonella will experience symptoms similar to a stomach flu, but the infection can be serious — and even fatal — for young children, elderly people, and those with a weak immune system.

Those who bought a recalled cake mix should throw it out or return it to the store where it was purchased.