Fix CI_Input::is_ajax_request()
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index c9354de..385eb48 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -101,6 +101,7 @@
 -  Fixed a bug (#904) - ``CI_Loader::initialize()`` caused a PHP Fatal error to be triggered if error level E_STRICT is used.
 -  Fixed a hosting edge case where an empty $_SERVER['HTTPS'] variable would evaluate to 'on'
 -  Fixed a bug (#154) - ``CI_Session::sess_update()`` caused the session to be destroyed on pages where multiple AJAX requests were executed at once.
+-  Fixed a possible bug in ``CI_Input::is_ajax_request()`` where some clients might not send the X-Requested-With HTTP header value exactly as 'XmlHttpRequest'.
 
 Version 2.1.0
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