diff --git a/chartjs/chart-tests.ts b/chartjs/chart-tests.ts
index 79a2692c2..2374b6228 100644
--- a/chartjs/chart-tests.ts
+++ b/chartjs/chart-tests.ts
@@ -1,5 +1,6 @@
 /// <reference path="chart.d.ts" />
 
+var canvas = <HTMLCanvasElement>document.getElementById('example-chart');
 var ctx = canvas.getContext('2d');
 
 Chart.defaults.global = {