diff --git a/samples/charts/doughnut.html b/samples/charts/doughnut.html
index 446dcee4e..8466970a4 100644
--- a/samples/charts/doughnut.html
+++ b/samples/charts/doughnut.html
@@ -23,6 +23,7 @@
 	<button id="removeDataset">Remove Dataset</button>
 	<button id="addData">Add Data</button>
 	<button id="removeData">Remove Data</button>
+	<button id="changeCircleSize">Semi/Full Circle</button>
 	<script>
 		var randomScalingFactor = function() {
 			return Math.round(Math.random() * 100);
@@ -138,6 +139,18 @@
 
 			window.myDoughnut.update();
 		});
+
+		document.getElementById('changeCircleSize').addEventListener('click', function() {
+			if (window.myDoughnut.options.circumference === Math.PI) {
+				window.myDoughnut.options.circumference = 2 * Math.PI;
+				window.myDoughnut.options.rotation = -Math.PI / 2;
+			} else {
+				window.myDoughnut.options.circumference = Math.PI;
+				window.myDoughnut.options.rotation = -Math.PI;
+			}
+
+			window.myDoughnut.update();
+		});
 	</script>
 </body>