diff --git a/lib/ace/edit_session.js b/lib/ace/edit_session.js
index e0cfd8cd..e9e9fadf 100644
--- a/lib/ace/edit_session.js
+++ b/lib/ace/edit_session.js
@@ -91,6 +91,9 @@ var EditSession = function(text, mode) {
         this.doc = doc;
         doc.on("change", this.onChange.bind(this));
         this.on("changeFold", this.onChangeFold.bind(this));
+        
+        this.bgTokenizer.setDocument(this.getDocument());
+        this.bgTokenizer.start(0);
     };
 
     this.getDocument = function() {