Clicking on label of Liferay AUI checkbox changes value of the preceding checkbox

I wrote this simple form in Liferay:

<aui:input type="checkbox" name="team" value="joe" label="joe" checked="false" />
<aui:input type="checkbox" name="team" value="ben" label="ben" checked="false" />

PROBLEM: When I click on the label "ben", the value of the joe checkbox changes.

Is my syntax incorrect?