diff --git a/lib/ace/editor.js b/lib/ace/editor.js
index 26fbb1c2..efa1cb9a 100644
--- a/lib/ace/editor.js
+++ b/lib/ace/editor.js
@@ -122,6 +122,7 @@ var Editor =function(renderer, session) {
         if (this.session == session) return;
 
         if (this.session) {
+            var oldSession = this.session;
             this.session.removeEventListener("change", this.$onDocumentChange);
             this.session.removeEventListener("changeMode", this.$onDocumentModeChange);
             this.session.removeEventListener("changeTabSize", this.$onDocumentChangeTabSize);
@@ -172,6 +173,11 @@ var Editor =function(renderer, session) {
         this.onDocumentChangeAnnotation();
         this.renderer.scrollToRow(session.getScrollTopRow());
         this.renderer.updateFull();
+        
+        this._dispatchEvent("changeSession", {
+            session: session,
+            oldSession: oldSession
+        });
     };
 
     this.getSession = function() {