diff --git a/extension.driver.php b/extension.driver.php
index 2b27c59..4b012c2 100644
--- a/extension.driver.php
+++ b/extension.driver.php
@@ -142,7 +142,7 @@ public function parseXML($context)
         }
 
         if (isset($_SERVER['HTTP_IF_NONE_MATCH']) and $etag === $_SERVER['HTTP_IF_NONE_MATCH']) {
-            header('HTTP/1.1 304 Not Modified');
+            header('Status: 304 Not Modified', true, 304)
             exit(0);
         }
     }