diff --git a/scripts/tune_port.php b/scripts/tune_port.php
index c38f41dd09..495c2ad823 100755
--- a/scripts/tune_port.php
+++ b/scripts/tune_port.php
@@ -5,6 +5,7 @@ require 'includes/defaults.inc.php';
 require 'config.php';
 require 'includes/definitions.inc.php';
 require 'includes/functions.php';
+rrdtool_pipe_open($rrd_process, $rrd_pipes);
 
 $options = getopt('h:p:');