diff --git a/src/opnsense/mvc/app/models/OPNsense/Base/FieldTypes/CSVListField.php b/src/opnsense/mvc/app/models/OPNsense/Base/FieldTypes/CSVListField.php
index b0baaa868..794fce9a4 100644
--- a/src/opnsense/mvc/app/models/OPNsense/Base/FieldTypes/CSVListField.php
+++ b/src/opnsense/mvc/app/models/OPNsense/Base/FieldTypes/CSVListField.php
@@ -84,7 +84,11 @@ class CSVListField extends BaseField
      */
     public function setMaskPerItem($value)
     {
-        $this->internalMaskPerItem = $value;
+        if (strtoupper(trim($value)) == "Y")  {
+            $this->internalMaskPerItem = true;
+        } else {
+            $this->internalMaskPerItem = false;
+        }
     }
 
     /**