diff --git a/src/wp-includes/class-IXR.php b/src/wp-includes/class-IXR.php
index ec3f70ca71..7cc4c20fb9 100644
--- a/src/wp-includes/class-IXR.php
+++ b/src/wp-includes/class-IXR.php
@@ -540,7 +540,6 @@ EOD;
             $xml = '<?xml version="1.0"?>'."\n".$xml;
         $length = strlen($xml);
         header('Connection: close');
-        header('Content-Length: '.$length);
         if ($charset)
             header('Content-Type: text/xml; charset='.$charset);
         else