diff --git a/lib/contents.php b/lib/contents.php
index 3074bd72d68..304d394e2ba 100644
--- a/lib/contents.php
+++ b/lib/contents.php
@@ -36,6 +36,7 @@ final class HttpException extends \Exception {}
 	'415' => 'Unsupported Media Type',
 	'416' => 'Requested Range Not Satisfiable',
 	'417' => 'Expectation Failed',
+	'429' => 'Too Many Requests',
 	'500' => 'Internal Server Error',
 	'501' => 'Not Implemented',
 	'502' => 'Bad Gateway',