diff --git a/booking.register.inc b/booking.register.inc
index d878e96..bd0f937 100644
--- a/booking.register.inc
+++ b/booking.register.inc
@@ -967,7 +967,7 @@ function booking_form_submit($form, &$form_state) {
 	$node->booking_welfare_required = empty($values['booking_welfare_required']) ? 'N' : ($values['booking_welfare_required'] == 1 ? 'Y' : 'N');
 	$node->booking_committee_member = empty($values['booking_committee_member']) ? 'N' : ($values['booking_committee_member'] == 1 ? 'Y' : 'N');
 	$node->booking_welfare_required = empty($values['booking_welfare_required']) ? 'N' : ($values['booking_welfare_required'] == 1 ? 'Y' : 'N');
-	$node->booking_refund_due = empty($values['booking_refund_due']) ? '' : $values['booking_refund_due'];
+	$node->booking_refund_due = empty($values['booking_refund_due']) ? 0 : $values['booking_refund_due'];
 	$node->booking_help_music = empty($values['booking_help_music']) ? '' : $values['booking_help_music'];
 	$node->booking_help_meditations = empty($values['booking_help_meditations']) ? '' : $values['booking_help_meditations'];
 	$node->booking_help_praying = empty($values['booking_help_praying']) ? '' : $values['booking_help_praying'];