diff --git a/lib/form/recaptcha.php b/lib/form/recaptcha.php
index d4f467ef7b14f..79b2cb1f9b1f8 100644
--- a/lib/form/recaptcha.php
+++ b/lib/form/recaptcha.php
@@ -1,4 +1,6 @@
 <?php
+require_once('HTML/QuickForm/input.php');
+
 /* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
 
 /**