diff --git a/examples/donut.html b/examples/donut.html
index 4487daf..752a047 100644
--- a/examples/donut.html
+++ b/examples/donut.html
@@ -19,7 +19,8 @@ Morris.Donut({
{value: 15, label: 'bar'},
{value: 10, label: 'baz'},
{value: 5, label: 'A really really long label'}
- ]
+ ],
+ formatter: function (x) { return x + "%"}
});