diff --git a/htdocs/compta/paiement/class/paiement.class.php b/htdocs/compta/paiement/class/paiement.class.php
index 6a8628da6c3..088e14c5543 100644
--- a/htdocs/compta/paiement/class/paiement.class.php
+++ b/htdocs/compta/paiement/class/paiement.class.php
@@ -292,7 +292,7 @@ class Paiement extends CommonObject
 									// Insert one discount by VAT rate category
 									$discount = new DiscountAbsolute($this->db);
 									$discount->fetch('',$invoice->id);
-									if (empty($discount->id)) {
+									if (empty($discount->id)) {	// If the invoice was not yet converted into a discount (this may have been done manually before we come here)
 
 
 										$discount->description = '(DEPOSIT)';