diff --git a/src/api/geom/linestring.js b/src/api/geom/linestring.js
index 52c89ff022..4debb2a62c 100644
--- a/src/api/geom/linestring.js
+++ b/src/api/geom/linestring.js
@@ -4,9 +4,14 @@ goog.require('ol.geom.LineString');
 goog.require('ol.geom.point');
 goog.require('ol.projection');
 
+/**
+ * @typedef {Array.<ol.PointLike>} linestring LineString.
+ */
+ol.LineStringLike;
+
 /**
  * @export
- * @param {Array.<ol.PointLike>} opt_arg Point.
+ * @param {ol.LineStringLike} opt_arg Points.
  * @return {ol.geom.LineString} LineString.
  */
 ol.geom.linestring = function(opt_arg){