diff --git a/src/definitions/modules/accordion.js b/src/definitions/modules/accordion.js
index 98cdb8810..9d4203ae8 100644
--- a/src/definitions/modules/accordion.js
+++ b/src/definitions/modules/accordion.js
@@ -92,7 +92,7 @@ $.fn.accordion = function(parameters) {
         },
 
         observeChanges: function() {
-          if(MutationObserver !== undefined) {
+          if('MutationObserver' in window) {
             observer = new MutationObserver(function(mutations) {
               module.debug('DOM tree modified, updating selector cache');
               module.refresh();
diff --git a/src/definitions/modules/checkbox.js b/src/definitions/modules/checkbox.js
index 7013f7620..d6aa35344 100644
--- a/src/definitions/modules/checkbox.js
+++ b/src/definitions/modules/checkbox.js
@@ -105,7 +105,7 @@ $.fn.checkbox = function(parameters) {
         },
 
         observeChanges: function() {
-          if(MutationObserver !== undefined) {
+          if('MutationObserver' in window) {
             observer = new MutationObserver(function(mutations) {
               module.debug('DOM tree modified, updating selector cache');
               module.refresh();
diff --git a/src/definitions/modules/dropdown.js b/src/definitions/modules/dropdown.js
index 05342c6f9..3a057f1a3 100644
--- a/src/definitions/modules/dropdown.js
+++ b/src/definitions/modules/dropdown.js
@@ -102,7 +102,7 @@ $.fn.dropdown = function(parameters) {
         },
 
         observeChanges: function() {
-          if(MutationObserver !== undefined) {
+          if('MutationObserver' in window) {
             observer = new MutationObserver(function(mutations) {
               module.debug('DOM tree modified, updating selector cache');
               module.refresh();
diff --git a/src/definitions/modules/sticky.js b/src/definitions/modules/sticky.js
index 4533029a8..aa115fcc2 100644
--- a/src/definitions/modules/sticky.js
+++ b/src/definitions/modules/sticky.js
@@ -122,7 +122,7 @@ $.fn.sticky = function(parameters) {
           var
             context = $context[0]
           ;
-          if(MutationObserver !== undefined) {
+          if('MutationObserver' in window) {
             observer = new MutationObserver(function(mutations) {
               clearTimeout(module.timer);
               module.timer = setTimeout(function() {