diff --git a/schemas/legacy.json b/schemas/legacy.json
index 35624c1..22e1e5f 100644
--- a/schemas/legacy.json
+++ b/schemas/legacy.json
@@ -1164,6 +1164,9 @@
             },
             "Presence": {
                 "properties": {
+                    "MonitorType": {
+                        "enum": ["Event", "Polling"]
+                    },
                     "PinName": {
                         "type": "string"
                     },