diff --git a/htdocs/core/class/discount.class.php b/htdocs/core/class/discount.class.php
index 6b5ba21be7b..d89db86aa10 100644
--- a/htdocs/core/class/discount.class.php
+++ b/htdocs/core/class/discount.class.php
@@ -689,6 +689,11 @@ class DiscountAbsolute
         global $langs;
 
         $result='';
+        $link = '';
+        $linkend = '';
+        $label = '';
+        $picto = '';
+        $ref = '';
 
         if ($option == 'invoice') {
             $facid=! empty($this->discount_type)?$this->fk_invoice_supplier_source:$this->fk_facture_source;