diff --git a/dist/image-sequencer.js b/dist/image-sequencer.js
index 319538c7..d971cb3a 100644
--- a/dist/image-sequencer.js
+++ b/dist/image-sequencer.js
@@ -184165,7 +184165,7 @@ ImageSequencer = function ImageSequencer(options) {
   function addStep(name, o) {
     console.log('adding step "' + name + '"');
 
-    if (!(options.instanceName) && window && this != window)
+    if (!(options.instanceName) && typeof(window) != undefined && this != window)
       for(var variable in window)
         if(window[variable] == this)
           options.instanceName = variable;
@@ -184253,7 +184253,7 @@ ImageSequencer = function ImageSequencer(options) {
   // i.e. from parameter
   // this could send the image to ImageSelect, or something?
   function loadImage(src, callback) {
-    if (!(options.instanceName) && window && this != window)
+    if (!(options.instanceName) && typeof(window) != undefined && this != window)
       for(var variable in window)
         if(window[variable] == this)
           options.instanceName = variable;
diff --git a/src/ImageSequencer.js b/src/ImageSequencer.js
index 5bc79e15..a520855a 100644
--- a/src/ImageSequencer.js
+++ b/src/ImageSequencer.js
@@ -19,7 +19,7 @@ ImageSequencer = function ImageSequencer(options) {
   function addStep(name, o) {
     console.log('adding step "' + name + '"');
 
-    if (!(options.instanceName) && window && this != window)
+    if (!(options.instanceName) && typeof(window) != undefined && this != window)
       for(var variable in window)
         if(window[variable] == this)
           options.instanceName = variable;
@@ -107,7 +107,7 @@ ImageSequencer = function ImageSequencer(options) {
   // i.e. from parameter
   // this could send the image to ImageSelect, or something?
   function loadImage(src, callback) {
-    if (!(options.instanceName) && window && this != window)
+    if (!(options.instanceName) && typeof(window) != undefined && this != window)
       for(var variable in window)
         if(window[variable] == this)
           options.instanceName = variable;