diff --git a/src/objectliterals.jsdoc b/src/objectliterals.jsdoc
index 5818a66a45..a27dae8aa2 100644
--- a/src/objectliterals.jsdoc
+++ b/src/objectliterals.jsdoc
@@ -245,6 +245,11 @@
  * @todo stability experimental
  */
 
+/**
+ * @typedef {Object} ol.format.GeoJSONOptions
+ * @property {ol.proj.ProjectionLike} projection Projection.
+ */
+
 /**
  * @typedef {Object} ol.interaction.DoubleClickZoomOptions
  * @property {number|undefined} duration Animation duration in milliseconds. Default is `250`.
diff --git a/src/ol/format/geojson/geojsonformat.js b/src/ol/format/geojson/geojsonformat.js
index 39bc2b311a..710582c209 100644
--- a/src/ol/format/geojson/geojsonformat.js
+++ b/src/ol/format/geojson/geojsonformat.js
@@ -19,8 +19,9 @@ goog.require('ol.geom.Polygon');
 /**
  * @constructor
  * @implements {ol.format.IReader}
+ * @param {ol.format.GeoJSONOptions=} opt_options Options.
  */
-ol.format.GeoJSON = function() {
+ol.format.GeoJSON = function(opt_options) {
 };