diff --git a/src/schedule.js b/src/schedule.js
index 0aace9c21..488e7a011 100644
--- a/src/schedule.js
+++ b/src/schedule.js
@@ -31,7 +31,8 @@ if (util.isNode && typeof MutationObserver === "undefined") {
 } else if ((typeof MutationObserver !== "undefined") &&
           !(typeof window !== "undefined" &&
             window.navigator &&
-            (window.navigator.standalone || window.cordova))) {
+            (window.navigator.standalone || window.cordova)) &&
+          ("classList" in document.documentElement)) {
     schedule = (function() {
         // Using 2 mutation observers to batch multiple updates into one.
         var div = document.createElement("div");