You definitely don’t eat the skin of an avocado so why would you need to wash the exterior before eating one? Turns out that the skin of an avocado can host bacteria that can find their way into the fruit’s green flesh, according to the FDA.

The FDA issued a report earlier this month, urging consumers to think twice before eating or preparing avocado after compiling data that showed Listeria monocytogenes was found on 17 percent of avocado samples taken from 2014 to 2016. The bacteria was found on the skin of the avocados sampled, but 0.2 percent of avocados involved in the sampling contained flesh that also tested positive for listeria.

The FDA’s report states that all avocados should be washed before opening because bacteria can easily transfer from the skin to the knife, which can then contaminate the inside of the avocado you’re preparing & any other food you’re serving along with it.

A listeria outbreak linked to avocados has still yet to occur in the US, but there’s more than one kind of bacteria to watch out for. Federal investigators are also monitoring the presence of salmonella on avocado skins the same report found just under one percent of avocados sampled carried salmonella on the skin. The FDA is continuing their investigation by also sampling ready-to-eat products containing avocado, such as packaged guacamole, for more harmful bacteria into 2019.

Listeria is uncommon in healthy adults, but the elderly, pregnant women, and those with weakened immune systems could be at greater risk for this illness. Symptoms include fever, nausea, muscle aches, vomiting, and chronic diarrhea in more severe cases it can lead to confusion, stiff neck, and convulsions.

So please do yourself a favor & wash your avocado before cutting it.