diff --git a/html/includes/graphs/common.inc.php b/html/includes/graphs/common.inc.php
index 9211db91f..5bce925d4 100644
--- a/html/includes/graphs/common.inc.php
+++ b/html/includes/graphs/common.inc.php
@@ -5,7 +5,7 @@ if ($_GET['to'])      { $to     = mres($_GET['to']);     }
 if ($_GET['width'])   { $width  = mres($_GET['width']);  }
 if($config['trim_tobias']) { $width+=12; }
 if ($_GET['height'])  { $height = mres($_GET['height']); }
-if ($_GET['inverse']) { $in = 'out'; $out = 'in'; } else { $in = 'in'; $out = 'out'; }
+if ($_GET['inverse']) { $in = 'out'; $out = 'in'; $inverse=TRUE; } else { $in = 'in'; $out = 'out'; }
 if ($_GET['legend'] == "no")  { $rrd_options .= " -g"; }
 
 if ($_GET['title'] == "yes")  { $rrd_options .= " --title='".$graph_title."' "; }