diff --git a/htdocs/core/class/commoninvoice.class.php b/htdocs/core/class/commoninvoice.class.php
index 86ef739d63e..2121330a751 100644
--- a/htdocs/core/class/commoninvoice.class.php
+++ b/htdocs/core/class/commoninvoice.class.php
@@ -201,7 +201,7 @@ abstract class CommonInvoice extends CommonObject
 	 * 		@param 		int 	$multicurrency 	Return multicurrency_amount instead of amount
 	 *		@return		int						<0 if KO, Sum of credit notes and deposits amount otherwise
 	 */
-	function getSumFromThisCreditNotesNotUsed($multicurrency=0)
+	public function getSumFromThisCreditNotesNotUsed($multicurrency=0)
 	{
 	    require_once DOL_DOCUMENT_ROOT.'/core/class/discount.class.php';
 
diff --git a/htdocs/core/class/discount.class.php b/htdocs/core/class/discount.class.php
index cb2ad44b90c..5ed79b7c2d5 100644
--- a/htdocs/core/class/discount.class.php
+++ b/htdocs/core/class/discount.class.php
@@ -636,7 +636,7 @@ class DiscountAbsolute
 	 *	@param		int			      $multicurrency	Return multicurrency_amount instead of amount
      *	@return		int					        		<0 if KO, Sum of credit notes and deposits amount otherwise
      */
-    function getSumFromThisCreditNotesNotUsed($invoice, $multicurrency=0)
+    public function getSumFromThisCreditNotesNotUsed($invoice, $multicurrency=0)
     {
         dol_syslog(get_class($this)."::getSumCreditNotesUsed", LOG_DEBUG);