Safari 11 Bug Fieldset-Legend with Overflow Hidden and Click

Since Safari 11 for Mac checkboxes (and links/other click-events) are inaccessible when placed in a <legend>, does anyone know of a workaround? JS fiddle contains a demo, neither the checkbox can be checked, nor the click-event fires. Both work in Safari 10.2, but not in Safari 11. Also when I set the legend to position: relative the legend disappears. Setting the fieldset from overflow: hidden to overflow: visible seems to work, but I'd like to keep it hidden, as this could have other consequences in other browsers. Thanks!

Codepen Demo