diff --git a/specification/web/resource-manager/Microsoft.Web/stable/2016-03-01/CommonDefinitions.json b/specification/web/resource-manager/Microsoft.Web/stable/2016-03-01/CommonDefinitions.json
index eda20e904adb..b5fad40b666f 100644
--- a/specification/web/resource-manager/Microsoft.Web/stable/2016-03-01/CommonDefinitions.json
+++ b/specification/web/resource-manager/Microsoft.Web/stable/2016-03-01/CommonDefinitions.json
@@ -1040,6 +1040,7 @@
      "enum": [
       "SystemAssigned"
      ],
+     "type": "string",
      "x-ms-enum": {
       "name": "ManagedServiceIdentityType",
       "modelAsString": true