diff --git a/html/pages/device/port/realtime.inc.php b/html/pages/device/port/realtime.inc.php
index 1e8109203e..2109dd9e4c 100644
--- a/html/pages/device/port/realtime.inc.php
+++ b/html/pages/device/port/realtime.inc.php
@@ -3,8 +3,8 @@
 ### FIXME - do this in a function and/or do it in graph-realtime.php
 
 
-if($_GET['optc']) {
-  $interval = $_GET['optc'];
+if($_GET['opte']) {
+  $interval = $_GET['opte'];
 } else {
   if($device['os'] == "linux") {
     $interval = "15";