diff --git a/src/Booking/LessonBooker.php b/src/Booking/LessonBooker.php
index f5e9590..585e6b3 100644
--- a/src/Booking/LessonBooker.php
+++ b/src/Booking/LessonBooker.php
@@ -196,7 +196,7 @@ class LessonBooker {
 				payerId: $payerId
 			);
 
-			// Apply any available credit while booking.
+			// Apply any available credit to a scheduled charge raised at booking.
 			if ( $offering->isScheduledBilling() && null !== $payment && null !== $payment->id && Payment::STATUS_PENDING === $payment->status ) {
 				$this->payments->applyCredits( $payerId, [ $payment ] );
 				$payment = $this->payments->findPayment( (int) $payment->id ) ?? $payment;