diff --git a/src/ol/format/geojsonformat.js b/src/ol/format/geojsonformat.js
index cdfc8a01b3..d873666950 100644
--- a/src/ol/format/geojsonformat.js
+++ b/src/ol/format/geojsonformat.js
@@ -561,7 +561,7 @@ ol.format.GeoJSON.prototype.writeFeaturesObject =
  *
  * @function
  * @param {ol.geom.Geometry} geometry Geometry.
- * @param {olx.format.WriteOptions} options Write options.
+ * @param {olx.format.WriteOptions=} opt_options Write options.
  * @return {string} GeoJSON.
  * @api stable
  */