diff --git a/htdocs/comm/propal/document.php b/htdocs/comm/propal/document.php
index 8e3bf45bf68..eca5ce52fa7 100644
--- a/htdocs/comm/propal/document.php
+++ b/htdocs/comm/propal/document.php
@@ -61,8 +61,8 @@ $offset = $conf->liste_limit * $page;
 $pageprev = $page - 1;
 $pagenext = $page + 1;
 
-if (isset($conf->global->MAIN_DOC_SORT_FIELD)){$sortfield=$conf->global->MAIN_DOC_SORT_FIELD;}
-if (isset($conf->global->MAIN_DOC_SORT_ORDER)){$sortorder=$conf->global->MAIN_DOC_SORT_ORDER;}
+if (! empty($conf->global->MAIN_DOC_SORT_FIELD)) { $sortfield=$conf->global->MAIN_DOC_SORT_FIELD; }
+if (! empty($conf->global->MAIN_DOC_SORT_ORDER)) { $sortorder=$conf->global->MAIN_DOC_SORT_ORDER; }
 
 if (! $sortorder) $sortorder="ASC";
 if (! $sortfield) $sortfield="name";