diff --git a/rest-api-spec/api/mlt.json b/rest-api-spec/api/mlt.json
index 4c3f6266e3f..476cf7ed1de 100644
--- a/rest-api-spec/api/mlt.json
+++ b/rest-api-spec/api/mlt.json
@@ -17,7 +17,7 @@
           "description" : "The name of the index"
         },
         "type": {
-            "type" : "string",
+          "type" : "string",
           "required" : true,
           "description" : "The type of the document (use `_all` to fetch the first document matching the ID across all types)"
         }