diff --git a/user_guide/libraries/output.html b/user_guide/libraries/output.html
index efb3346..7af2b35 100644
--- a/user_guide/libraries/output.html
+++ b/user_guide/libraries/output.html
@@ -96,7 +96,7 @@
 $this->output->set_header("HTTP/1.1 200 OK");<br />
 $this->output->set_header('Last-Modified: '.gmdate('D, d M Y H:i:s', $last_update).' GMT');<br />
 $this->output->set_header("Cache-Control: no-store, no-cache, must-revalidate");<br />
-$this->output->set_header("Cache-Control: post-check=0, pre-check=0", false);<br />
+$this->output->set_header("Cache-Control: post-check=0, pre-check=0");<br />
 $this->output->set_header("Pragma: no-cache");	</code>