diff --git a/LibreNMS/OS/Ciscowlc.php b/LibreNMS/OS/Ciscowlc.php
index bd46e7d70e..83291e18fd 100644
--- a/LibreNMS/OS/Ciscowlc.php
+++ b/LibreNMS/OS/Ciscowlc.php
@@ -52,7 +52,7 @@ class Ciscowlc extends Cisco implements
 
         foreach ($radios as $radio) {
             foreach ($radio as $slot) {
-                $numClients += $slot['AIRESPACE-WIRELESS-MIB::bsnApIfNoOfUsers'];
+                $numClients += $slot['AIRESPACE-WIRELESS-MIB::bsnApIfNoOfUsers'] ?? 0;
             }
         }