diff --git a/data/schemas/definitions.jsonschema b/data/schemas/definitions.jsonschema
index 3f92e289a7..9fd503a108 100644
--- a/data/schemas/definitions.jsonschema
+++ b/data/schemas/definitions.jsonschema
@@ -51,6 +51,10 @@
     },
     "mcu_pin": {
         "oneOf": [
+            {
+                "type": "string",
+                "enum": ["NO_PIN"]
+            },
             {
                 "type": "string",
                 "pattern": "^[A-K]\\d{1,2}$"