The Georgia-based company Alma Pak International LLC is voluntarily recalling 400 30-pound boxes of organic blueberries due to a high risk of listeria contamination, according to the U.S. Food and Drug Administration. The recall was initiated on June 9 and categorized as a Class I recall by the FDA on July 1.

Listeria infections can cause serious illness, particularly in older adults, people with weakened immune systems and those who are pregnant or their newborns.

There’s a “reasonable probability” the recalled fruit will cause serious illness or death, the U.S. Food and Drug Administration warns.