diff --git a/specification/resources/resource-manager/Microsoft.Resources/stable/2018-02-01/resources.json b/specification/resources/resource-manager/Microsoft.Resources/stable/2018-02-01/resources.json
index 4620d6830dc1..a2e2b2c823eb 100644
--- a/specification/resources/resource-manager/Microsoft.Resources/stable/2018-02-01/resources.json
+++ b/specification/resources/resource-manager/Microsoft.Resources/stable/2018-02-01/resources.json
@@ -2528,6 +2528,11 @@
           "type": "string",
           "description": "The tenant ID of resource."
         },
+        "identities": {
+          "additionalProperties": {
+            "$ref": "#/definitions/UserDefinedIdentity"
+          }
+        },
         "type": {
           "type": "string",
           "description": "The identity type.",
@@ -2545,6 +2550,19 @@
       },
       "description": "Identity for the resource."
     },
+    "UserDefinedIdentity": {
+      "properties": {
+        "clientId": {
+          "type": "string"
+        },
+        "principalId": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "clientId", "principalId"
+      ]
+    },
     "ResourceListResult": {
       "properties": {
         "value": {
@@ -2961,4 +2979,4 @@
       "description": "The API version to use for this operation."
     }
   }
-}
+}
\ No newline at end of file