diff --git a/lib/ace/edit_session.js b/lib/ace/edit_session.js
index 44a83ff1..98125892 100644
--- a/lib/ace/edit_session.js
+++ b/lib/ace/edit_session.js
@@ -439,15 +439,11 @@ var EditSession = function(text, mode) {
         if (this.$useWorker == useWorker)
             return;
 
-        if (useWorker && !this.$worker && window.Worker)
-            this.$worker = mode.createWorker(this);
-
-        if (!useWorker && this.$worker) {
-            this.$worker.terminate();
-            this.$worker = null;
-        }
-
         this.$useWorker = useWorker;
+
+        this.$stopWorker();
+        if (useWorker)
+            this.$startWorker();
     };
 
     this.getUseWorker = function() {
@@ -463,14 +459,12 @@ var EditSession = function(text, mode) {
     this.$mode = null;
     this.setMode = function(mode) {
         if (this.$mode === mode) return;
+        this.$mode = mode;
 
-        if (this.$worker)
-            this.$worker.terminate();
+        this.$stopWorker();
 
-        if (this.$useWorker && typeof Worker !== "undefined" && !require.noWorker)
-            this.$worker = mode.createWorker(this);
-        else
-            this.$worker = null;
+        if (this.$useWorker)    
+            this.$startWorker();
 
         var tokenizer = mode.getTokenizer();
 
@@ -492,10 +486,30 @@ var EditSession = function(text, mode) {
         this.bgTokenizer.setDocument(this.getDocument());
         this.bgTokenizer.start(0);
 
-        this.$mode = mode;
         this._dispatchEvent("changeMode");
     };
 
+    this.$stopWorker = function() {
+        if (this.$worker)
+            this.$worker.terminate();
+        
+        this.$worker = null;
+    };
+    
+    this.$startWorker = function() {
+        if (typeof Worker !== "undefined" && !require.noWorker) {
+            try {
+                this.$worker = this.$mode.createWorker(this);
+            } catch (e) {
+                console.log("Could not load worker");
+                console.log(e);
+                this.$worker = null;                
+            }
+        }
+        else
+            this.$worker = null;
+    };
+
     this.getMode = function() {
         return this.$mode;
     };