diff --git a/lib/types/objectid.js b/lib/types/objectid.js
index 44ad43f4983..1282b9163ec 100644
--- a/lib/types/objectid.js
+++ b/lib/types/objectid.js
@@ -18,26 +18,3 @@ var driver = global.MONGOOSE_DRIVER_PATH || '../drivers/node-mongodb-native';
 var ObjectId = require(driver + '/objectid');
 module.exports = ObjectId;
 
-/**
- * Creates an ObjectId from `str`
- *
- * @param {ObjectId|HexString} str
- * @static fromString
- * @receiver ObjectId
- * @return {ObjectId}
- * @api private
- */
-
-ObjectId.fromString;
-
-/**
- * Converts `oid` to a string.
- *
- * @param {ObjectId} oid ObjectId instance
- * @static toString
- * @receiver ObjectId
- * @return {String}
- * @api private
- */
-
-ObjectId.toString;