diff --git a/html/includes/graphs/device/nfsen_common.inc.php b/html/includes/graphs/device/nfsen_common.inc.php
index 774d47e3f8..c51d7dcd95 100644
--- a/html/includes/graphs/device/nfsen_common.inc.php
+++ b/html/includes/graphs/device/nfsen_common.inc.php
@@ -7,7 +7,7 @@ if (!is_array($config['nfsen_rrds'])) {
 }
 
 foreach ($config['nfsen_rrds'] as $nfsenrrds) {
-    if ($configs[(strlen($nfsenrrds) - 1)] != '/') {
+    if ($nfsenrrds[(strlen($nfsenrrds) - 1)] != '/') {
         $nfsenrrds .= '/';
     }
 
diff --git a/html/pages/device.inc.php b/html/pages/device.inc.php
index 8f42abff83..33d643510e 100644
--- a/html/pages/device.inc.php
+++ b/html/pages/device.inc.php
@@ -360,7 +360,7 @@ if (device_permitted($vars['device']) || $check_device == $vars['device']) {
             }
 
             foreach ($config['nfsen_rrds'] as $nfsenrrds) {
-                if ($configs[(strlen($nfsenrrds) - 1)] != '/') {
+                if ($nfsenrrds[(strlen($nfsenrrds) - 1)] != '/') {
                     $nfsenrrds .= '/';
                 }