diff --git a/src/wp-includes/default-constants.php b/src/wp-includes/default-constants.php
index 774446e9e4..c9092bd2cc 100644
--- a/src/wp-includes/default-constants.php
+++ b/src/wp-includes/default-constants.php
@@ -354,6 +354,6 @@ function wp_templating_constants() {
 	 * @see WP_Theme::get_core_default_theme()
 	 */
 	if ( !defined('WP_DEFAULT_THEME') )
-		define( 'WP_DEFAULT_THEME', 'twentyfifteen' );
+		define( 'WP_DEFAULT_THEME', 'twentysixteen' );
 
 }