diff --git a/tests/test.display.js b/tests/test.display.js
index f44f6c66..05dd8a70 100644
--- a/tests/test.display.js
+++ b/tests/test.display.js
@@ -223,6 +223,7 @@ describe('Display/Canvas Helper', function () {
             display = new Display(canvas);
             display.clipViewport = true;
             display.resize(4, 3);
+            display.viewportChangeSize(4, 3);
             document.body.appendChild(canvas);
         });