diff --git a/src/main/js/lib/events-canary.js b/src/main/js/lib/events-canary.js
index 19b264e..1b90657 100644
--- a/src/main/js/lib/events-canary.js
+++ b/src/main/js/lib/events-canary.js
@@ -1,3 +1,4 @@
+/*global nashorn, exports, require, Packages, __plugin*/
 var cmPriority = Packages.net.canarymod.plugin.Priority,
   cmCanary = Packages.net.canarymod.Canary,
   cmDispatcher = Packages.net.canarymod.hook.Dispatcher,
@@ -40,13 +41,10 @@ exports.on = function(
    The workaround is to make the ScriptCraftPlugin java class a Listener.
    Should only unregister() registered plugins in ScriptCraft js code.
    */
-  try {
+  if (nashorn){
     // nashorn
-    eventType = eventType.class;
-  } catch ( e ){
-    // non-nashorn
-    eventType = eventType;
-  }
+    eventType = require('nashorn-type')(eventType);
+  } 
   regd = new cmPluginListener({});
   cmHookExecutor.registerHook(regd, __plugin, eventType, eventExecutor, priority);
   result.unregister = function(){
diff --git a/src/main/js/lib/nashorn-type.js b/src/main/js/lib/nashorn-type.js
new file mode 100644
index 0000000..ad3f731
--- /dev/null
+++ b/src/main/js/lib/nashorn-type.js
@@ -0,0 +1,8 @@
+/*
+ The .class operator causes problems for non-nashorn Java on Mac OS X and some other 
+ environments. So need to have it in a separate module which should only be loaded in
+ nashorn environment.
+*/
+module.exports = function(t){
+  return t.class;
+};
diff --git a/src/main/js/lib/scriptcraft.js b/src/main/js/lib/scriptcraft.js
index 73ee136..7261b9f 100644
--- a/src/main/js/lib/scriptcraft.js
+++ b/src/main/js/lib/scriptcraft.js
@@ -383,6 +383,7 @@ This function takes a single parameter and returns true if it's an operator or h
 */
 var global = this;
 var server;
+global.nashorn = typeof Java !== 'undefined';
 /*
   private implementation
 */
@@ -624,7 +625,7 @@ function __onEnable ( __engine, __plugin, __script ) {
         /*
          wph 20140312 don't delete self on nashorn until https://bugs.openjdk.java.net/browse/JDK-8034055 is fixed
          */
-        if ( typeof Java === 'undefined' ) { // Java is an object in Nashorn
+        if ( !nashorn ) { 
           delete global.self;
           delete global.__engine;
         }
diff --git a/src/main/js/modules/canary/items.js b/src/main/js/modules/canary/items.js
index 7fabbac..b1c714f 100644
--- a/src/main/js/modules/canary/items.js
+++ b/src/main/js/modules/canary/items.js
@@ -29,11 +29,11 @@ function getMaterialHandler( material ){
     }
   };
 }
-try {
+if (nashorn){
   /*
    nashorn
    */
-  var itemTypeClass = ItemType.class;
+  var itemTypeClass = require('nashorn-type')(ItemType);
   var materials = itemTypeClass.getDeclaredFields();
   for (var i = 0;i < materials.length; i++ ){
 
@@ -48,19 +48,18 @@ try {
     
     items[name] = getMaterialHandler(materialField.get(ItemType));
   }
-} catch ( e ){
+} else {
   // non-nashorn
   for (var field in ItemType){
     if (ItemType[field] === undefined){
       continue;
     }
-    if (ItemType[field].class != ItemType){
+    if (!(ItemType[field] instanceof ItemType)){
       continue;
     }
     var name = (''+field).replace(/^(.)/,function(a){
       return a.toLowerCase();
     });
-    console.log(name);
     items[name] = getMaterialHandler(ItemType[field]);
   }
 }