diff --git a/admin/cat_list.php b/admin/cat_list.php
index 25ff9ea76..4f32b5ee1 100644
--- a/admin/cat_list.php
+++ b/admin/cat_list.php
@@ -30,7 +30,7 @@ $query.= ' FROM '.PREFIX_TABLE.'categories';
 $query.= ';';
 $row = mysql_fetch_array( mysql_query( $query ) );
 if ( $row['nb_total_categories'] < $conf['max_LOV_categories']
-     or $_GET['expand'] == 'all' )
+     or ( isset( $_GET['expand'] ) and $_GET['expand'] == 'all' ) )
 {
   $page['tab_expand'] = array();
   $page['expand'] = 'all';
diff --git a/index.php b/index.php
index 3ac140699..2bb4ec48d 100644
--- a/index.php
+++ b/index.php
@@ -17,7 +17,7 @@
  *                                                                         *
  ***************************************************************************/
 
-define( PREFIX_INCLUDE, '' );
+define( 'PREFIX_INCLUDE', '' );
 include_once( './include/functions.inc.php' );
 database_connection();
 // retrieving configuration informations