diff --git a/specification/datamigration/resource-manager/Microsoft.DataMigration/preview/2018-07-15-preview/definitions/MigrateSqlServerSqlMITask.json b/specification/datamigration/resource-manager/Microsoft.DataMigration/preview/2018-07-15-preview/definitions/MigrateSqlServerSqlMITask.json
index 5339b335b7ab..3ec1fed7ef0f 100644
--- a/specification/datamigration/resource-manager/Microsoft.DataMigration/preview/2018-07-15-preview/definitions/MigrateSqlServerSqlMITask.json
+++ b/specification/datamigration/resource-manager/Microsoft.DataMigration/preview/2018-07-15-preview/definitions/MigrateSqlServerSqlMITask.json
@@ -58,7 +58,11 @@
         "backupMode": {
           "$ref": "./TasksCommon.json#/definitions/BackupMode",
           "description": "Backup Mode to specify whether to use existing backup or create new backup. If using existing backups, backup file paths are required to be provided in selectedDatabases."
-        }
+        },
+        "aadDomainName": {
+          "type": "string",
+          "description": "Azure Active Directory domain name in the format of 'contoso.com' for federated Azure AD or 'contoso.onmicrosoft.com' for managed domain, required if and only if Windows logins are selected"
+    }
       },
       "required": [
         "selectedDatabases",