diff --git a/src/opnsense/mvc/app/models/OPNsense/Interfaces/FieldTypes/DUIDField.php b/src/opnsense/mvc/app/models/OPNsense/Interfaces/FieldTypes/DUIDField.php
index a199a52a90..134257b4e1 100644
--- a/src/opnsense/mvc/app/models/OPNsense/Interfaces/FieldTypes/DUIDField.php
+++ b/src/opnsense/mvc/app/models/OPNsense/Interfaces/FieldTypes/DUIDField.php
@@ -50,7 +50,11 @@ class DUIDField extends TextField
         $duid_length = count($values);
         $test1 = hexdec($values[1]);
         $test2 = hexdec($values[3]);
-        if (($test1 == 1 && $test2 == 1 ) || ($test1 == 3 && $test2 == 1 ) || ($test1 == 4) || ($test1 == 2)) {
+        if (($test1 == 1 && $test2 == 1) || ($test1 == 3 && $test2 == 1) || $test1 == 4 || $test1 == 2) {
+            $valid_duid = true;
+        }
+        if ($test1 == 0 && $test2 == 4) {
+            /* XXX accept these faulty DUIDs we accepted previously */
             $valid_duid = true;
         }