diff --git a/htdocs/supplier_proposal/card.php b/htdocs/supplier_proposal/card.php
index 5756149e74d..09f12d70e4a 100644
--- a/htdocs/supplier_proposal/card.php
+++ b/htdocs/supplier_proposal/card.php
@@ -686,6 +686,7 @@ if (empty($reshook)) {
 					$ref_supplier = $productsupplier->ref_supplier;
 
 					// Get vat rate
+					$tva_npr = 0;
 					if (!GETPOSTISSET('tva_tx')) {	// If vat rate not provided from the form (the form has the priority)
 						$tva_tx = get_default_tva($object->thirdparty, $mysoc, $productsupplier->id, GETPOST('idprodfournprice', 'alpha'));
 						$tva_npr = get_default_npr($object->thirdparty, $mysoc, $productsupplier->id, GETPOST('idprodfournprice', 'alpha'));
@@ -841,10 +842,10 @@ if (empty($reshook)) {
 				if (empty($conf->global->MAIN_DISABLE_PDF_AUTOUPDATE)) {
 					$outputlangs = $langs;
 					$newlang = '';
-					if ($conf->global->MAIN_MULTILANGS && empty($newlang) && GETPOST('lang_id', 'aZ09')) {
+					if (!empty($conf->global->MAIN_MULTILANGS) && empty($newlang) && GETPOST('lang_id', 'aZ09')) {
 						$newlang = GETPOST('lang_id', 'aZ09');
 					}
-					if ($conf->global->MAIN_MULTILANGS && empty($newlang)) {
+					if (!empty($conf->global->MAIN_MULTILANGS) && empty($newlang)) {
 						$newlang = $object->thirdparty->default_lang;
 					}
 					if (!empty($newlang)) {