diff --git a/playground/matplus/thies-marwitz/create-part-information-schema.json b/playground/matplus/thies-marwitz/create-part-information-schema.json
index 435d1846..59ad3364 100644
--- a/playground/matplus/thies-marwitz/create-part-information-schema.json
+++ b/playground/matplus/thies-marwitz/create-part-information-schema.json
@@ -12,6 +12,11 @@
       "title": "Part Number",
       "default": "12345"
     },
+    "serialNumber": {
+      "type": "string",
+      "title": "Serial Number",
+      "default": "01"
+    },
     "serialNumber": {
       "type": "string",
       "title": "Serial Number",