diff --git a/htdocs/admin/modules.php b/htdocs/admin/modules.php
index 53c497c74fe..ce67595a0f7 100644
--- a/htdocs/admin/modules.php
+++ b/htdocs/admin/modules.php
@@ -51,9 +51,9 @@ $search_version=GETPOST('search_version','alpha');
 // For dolistore search
 $options              = array();
 $options['per_page']  = 20;
-$options['categorie'] = GETPOST('categorie', 'int') + 0;
-$options['start']     = GETPOST('start', 'int') + 0;
-$options['end']       = GETPOST('end', 'int') + 0;
+$options['categorie'] = ((GETPOST('categorie', 'int')?GETPOST('categorie', 'int'):0) + 0);
+$options['start']     = ((GETPOST('start', 'int')?GETPOST('start', 'int'):0) + 0);
+$options['end']       = ((GETPOST('end', 'int')?GETPOST('end', 'int'):0) + 0);
 $options['search']    = GETPOST('search_keyword', 'alpha');
 $dolistore            = new Dolistore($options);