diff --git a/externs/geojson.js b/externs/geojson.js
index acb4821c0e..0352da86e2 100644
--- a/externs/geojson.js
+++ b/externs/geojson.js
@@ -95,6 +95,12 @@ var GeoJSONFeature = function() {};
 GeoJSONFeature.prototype.geometry;
 
 
+/**
+ * @type {number|string|undefined}
+ */
+GeoJSONFeature.prototype.id;
+
+
 /**
  * @type {Object.<string, *>}
  */