diff --git a/library/Icinga/Chart/Graph/LineGraph.php b/library/Icinga/Chart/Graph/LineGraph.php
index 05f3a310f..bd1c7647b 100644
--- a/library/Icinga/Chart/Graph/LineGraph.php
+++ b/library/Icinga/Chart/Graph/LineGraph.php
@@ -45,6 +45,12 @@ class LineGraph extends Styleable implements Drawable
      */
     private $tooltips;
 
+    /** @var array */
+    private $graphs;
+
+    /** @var int */
+    private $order;
+
     /**
      * The default stroke width
      * @var int