diff --git a/src/echo.js b/src/echo.js
index 4e89920..20b2510 100644
--- a/src/echo.js
+++ b/src/echo.js
@@ -12,11 +12,11 @@ window.Echo = (function (window, document, undefined) {
 
   var _pollImages = function () {
     for (var i = 0; i < store.length; i++) {
-      var self = store[i];
+      var self = store[i], array = Array.prototype;
       if (_inView(self)) {
         self.src = self.getAttribute('data-echo');
-        if (store.indexOf(self) !== -1) {
-          store.splice(i, 1);
+        if (array.indexOf.call(store, self) !== -1) {
+          array.splice.call(store, i, 1);
         }
       }
     }