diff --git a/js/load-image-fetch.js b/js/load-image-fetch.js
index 9ca1ccd..6778fea 100644
--- a/js/load-image-fetch.js
+++ b/js/load-image-fetch.js
@@ -25,7 +25,7 @@
 }(function (loadImage) {
   'use strict'
 
-  if ('fetch' in window && 'Request' in window) {
+  if (typeof fetch !== 'undefined' && typeof Request !== 'undefined') {
     loadImage.fetchBlob = function (url, callback, options) {
       if (loadImage.hasMetaOption(options)) {
         return fetch(new Request(url, options)).then(function (response) {
diff --git a/js/load-image-meta.js b/js/load-image-meta.js
index fc76958..3abd119 100644
--- a/js/load-image-meta.js
+++ b/js/load-image-meta.js
@@ -29,7 +29,7 @@
 }(function (loadImage) {
   'use strict'
 
-  var hasblobSlice = window.Blob && (Blob.prototype.slice ||
+  var hasblobSlice = typeof Blob !== 'undefined' && (Blob.prototype.slice ||
   Blob.prototype.webkitSlice || Blob.prototype.mozSlice)
 
   loadImage.blobSlice = hasblobSlice && function () {
@@ -55,7 +55,7 @@
     var that = this
     // 256 KiB should contain all EXIF/ICC/IPTC segments:
     var maxMetaDataSize = options.maxMetaDataSize || 262144
-    var noMetaData = !(window.DataView && file && file.size >= 12 &&
+    var noMetaData = !(typeof DataView !== 'undefined' && file && file.size >= 12 &&
                       file.type === 'image/jpeg' && loadImage.blobSlice)
     if (noMetaData || !loadImage.readFile(
         loadImage.blobSlice.call(file, 0, maxMetaDataSize),
diff --git a/js/load-image.js b/js/load-image.js
index 3d3ac94..c95330a 100644
--- a/js/load-image.js
+++ b/js/load-image.js
@@ -61,9 +61,9 @@
   }
   // The check for URL.revokeObjectURL fixes an issue with Opera 12,
   // which provides URL.createObjectURL but doesn't properly implement it:
-  var urlAPI = (window.createObjectURL && window) ||
-                (window.URL && URL.revokeObjectURL && URL) ||
-                (window.webkitURL && webkitURL)
+  var urlAPI = ($.createObjectURL && $) ||
+                ($.URL && URL.revokeObjectURL && URL) ||
+                ($.webkitURL && webkitURL)
 
   function revokeHelper (img, options) {
     if (img._objectURL && !(options && options.noRevoke)) {
@@ -135,4 +135,4 @@
   } else {
     $.loadImage = loadImage
   }
-}(window))
+}(this))