diff --git a/lib/errors/authenticationerror.js b/lib/errors/authenticationerror.js
index 2b1da147..1263e6d9 100644
--- a/lib/errors/authenticationerror.js
+++ b/lib/errors/authenticationerror.js
@@ -13,7 +13,7 @@ function AuthenticationError(message, status) {
 }
 
 // Inherit from `Error`.
-AuthenticationError.prototype.__proto__ = Error.prototype;
+Object.setPrototypeOf(AuthenticationError.prototype, Error.prototype);
 
 
 // Expose constructor.