diff --git a/wp-includes/default-constants.php b/wp-includes/default-constants.php
index c61076ed8a..0ba447fda6 100644
--- a/wp-includes/default-constants.php
+++ b/wp-includes/default-constants.php
@@ -294,7 +294,7 @@ function wp_templating_constants( ) {
 	 * @since 3.0.0
 	 */
 	if ( !defined('WP_DEFAULT_THEME') )
-		define( 'WP_DEFAULT_THEME', 'twentyten' );
+		define( 'WP_DEFAULT_THEME', 'twentyeleven' );
 
 }