diff --git a/htdocs/compta/facture/class/facture.class.php b/htdocs/compta/facture/class/facture.class.php
index 68fb0f602db..fafb4ce51fe 100644
--- a/htdocs/compta/facture/class/facture.class.php
+++ b/htdocs/compta/facture/class/facture.class.php
@@ -2146,7 +2146,8 @@ class Facture extends CommonInvoice
                 if (!empty($conf->global->INVOICE_USE_SITUATION))
                 {
     				$final = True;
-    				while ($i < count($this->lines) && $final == True) {
+    				$nboflines = count($this->lines);
+    				while (($i < $nboflines) && $final) {
     					$final = ($this->lines[$i]->situation_percent == 100);
     					$i++;
     				}