diff --git a/init.php b/init.php
index 690a237fc..5864cb01c 100644
--- a/init.php
+++ b/init.php
@@ -92,6 +92,7 @@
 require(dirname(__FILE__) . '/lib/SubscriptionItem.php');
 require(dirname(__FILE__) . '/lib/ThreeDSecure.php');
 require(dirname(__FILE__) . '/lib/Token.php');
+require(dirname(__FILE__) . '/lib/Topup.php');
 require(dirname(__FILE__) . '/lib/Transfer.php');
 require(dirname(__FILE__) . '/lib/TransferReversal.php');