diff --git a/includes/rrdtool.inc.php b/includes/rrdtool.inc.php
index 39d65655e6..f56557cd45 100644
--- a/includes/rrdtool.inc.php
+++ b/includes/rrdtool.inc.php
@@ -24,6 +24,8 @@
  * @author     Tony Murray <murraytony@gmail.com>
  */
 
+use LibreNMS\Config;
+
 /**
  * Generates a graph file at $graph_file using $options
  * Opens its own rrdtool pipe.