diff --git a/htdocs/accountancy/customer/lines.php b/htdocs/accountancy/customer/lines.php
index ed44277d7bf..673e927fbeb 100644
--- a/htdocs/accountancy/customer/lines.php
+++ b/htdocs/accountancy/customer/lines.php
@@ -64,7 +64,7 @@ $limit = GETPOST('limit','int')?GETPOST('limit', 'int'):(empty($conf->global->AC
 $sortfield = GETPOST('sortfield', 'alpha');
 $sortorder = GETPOST('sortorder', 'alpha');
 $page = GETPOST('page', 'int');
-if ($page < 0) $page = 0;
+if (empty($page) || $page < 0) $page = 0;
 $pageprev = $page - 1;
 $pagenext = $page + 1;
 $offset = $limit * $page;