diff --git a/htdocs/comm/propal/card.php b/htdocs/comm/propal/card.php
index e77910d784d..f69f41400c7 100644
--- a/htdocs/comm/propal/card.php
+++ b/htdocs/comm/propal/card.php
@@ -262,10 +262,10 @@ 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)) {
diff --git a/htdocs/product/class/propalmergepdfproduct.class.php b/htdocs/product/class/propalmergepdfproduct.class.php
index 6d15968af83..5892a4fe810 100644
--- a/htdocs/product/class/propalmergepdfproduct.class.php
+++ b/htdocs/product/class/propalmergepdfproduct.class.php
@@ -258,7 +258,7 @@ class Propalmergepdfproduct extends CommonObject
 					$line->import_key = $obj->import_key;
 
 
-					if ($conf->global->MAIN_MULTILANGS) {
+					if (!empty($conf->global->MAIN_MULTILANGS)) {
 						$this->lines[$obj->file_name.'_'.$obj->lang] = $line;
 					} else {
 						$this->lines[$obj->file_name] = $line;