diff --git a/application/libraries/MY_Session.php b/application/libraries/MY_Session.php
new file mode 100644
index 000000000..05b165374
--- /dev/null
+++ b/application/libraries/MY_Session.php
@@ -0,0 +1,19 @@
+<?php
+class MY_Session extends CI_Session {
+
+    /**
+     * Update an existing session
+     *
+     * @access    public
+     * @return    void
+    */
+    function sess_update() {
+       // skip the session update if this is an AJAX call! This is a bug in CI; see:
+       // https://github.com/EllisLab/CodeIgniter/issues/154
+       // http://codeigniter.com/forums/viewthread/102456/P15
+       if ( !($this->CI->input->is_ajax_request()) ) {
+           parent::sess_update();
+       }
+    }
+}
+