diff --git a/externs/olx.js b/externs/olx.js
index 7b50b3dd09..50b8b4f5b9 100644
--- a/externs/olx.js
+++ b/externs/olx.js
@@ -1637,6 +1637,7 @@ olx.format.GPXOptions.prototype.readExtensions;
 /**
  * @typedef {{featureNS: string,
  *     featureType: string,
+ *     gmlFormat: (ol.format.GMLBase|undefined),
  *     schemaLocation: (string|undefined)}}
  * @api
  */
@@ -1659,6 +1660,14 @@ olx.format.WFSOptions.prototype.featureNS;
 olx.format.WFSOptions.prototype.featureType;
 
 
+/**
+ * The GML format to use to parse the response. Default is `ol.format.GML3`.
+ * @type {ol.format.GMLBase|undefined}
+ * @api
+ */
+olx.format.WFSOptions.prototype.gmlFormat;
+
+
 /**
  * Optional schemaLocation to use for serialization, this will override the
  * default.