diff --git a/libraries/server_status_monitor.lib.php b/libraries/server_status_monitor.lib.php
index 8b8e40289c..5ab1c02f1e 100644
--- a/libraries/server_status_monitor.lib.php
+++ b/libraries/server_status_monitor.lib.php
@@ -587,7 +587,7 @@ function PMA_getJsonForChartingDataSwitch(
             $memory = $sysinfo->memory();
         }
 
-        $ret['value'] = $memory[$pName];
+        $ret['value'] = isset($memory[$pName]) ? $memory[$pName] : 0;
         break;
     }