Updated

A family in Colorado has proved why it’s always important to look at the expiration dates before buying groceries.

After getting home from Walmart on Monday, the Carelses — of Lakewood, Colo. — realized that they had purchased a box of Quaker 100% Natural Granola cereal that was more than two decades old.

Only problem was, they didn’t notice until after they started eating it.

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The Colorado family soon realized their Quaker 100% Natural Granola cereal that was more than two decades old. (Quaker Oats)

“I had about two bites, and that was it,” Andrea Carelse told Denver 7. Her husband, Josiah, scarfed down an entire bowl.

“I just started eating and thinking, ‘It just tastes funny. It must be OK,’” he said, noting how his wife had warned him to stop.

“I was like, ‘Josiah, you’re going to be really sick,'” Andrea remembered.

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Luckily for him, the cereal — which was dated Feb. 22, 1997 — didn’t cause any problems.

“We just grabbed this off the shelf and yeah… 21 years old,” Josiah said.

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Denver 7 reached out to Walmart and PepsiCo, Quaker’s parent company, for comment on the stomach-churning purchase. While Pepsi didn’t respond, Walmart said it was looking into the incident.

This story originally appeared in the New York Post.