diff --git a/src/openseadragon.js b/src/openseadragon.js
index ed43ff77..c0586583 100644
--- a/src/openseadragon.js
+++ b/src/openseadragon.js
@@ -1662,7 +1662,7 @@ window.OpenSeadragon = window.OpenSeadragon || function( options ){
 
 
         // polyfill, when necessary
-        if ( w.requestAnimationFrame ) {
+        if ( w.requestAnimationFrame && w.cancelAnimationFrame ) {
             //we cant assign window.requestAnimationFrame directly to $.requestAnimationFrame
             //without getting Illegal Invocation errors in webkit so call in a
             //wrapper