diff --git a/wp-admin/includes/schema.php b/wp-admin/includes/schema.php
index 3e7b11ffc5..27819b3e52 100644
--- a/wp-admin/includes/schema.php
+++ b/wp-admin/includes/schema.php
@@ -247,8 +247,8 @@ function populate_options() {
 	'default_email_category' => 1,
 	'recently_edited' => '',
 	'use_linksupdate' => 0,
-	'template' => WP_FALLBACK_THEME,
-	'stylesheet' => WP_FALLBACK_THEME,
+	'template' => WP_DEFAULT_THEME,
+	'stylesheet' => WP_DEFAULT_THEME,
 	'comment_whitelist' => 1,
 	'blacklist_keys' => '',
 	'comment_registration' => 0,
diff --git a/wp-includes/default-constants.php b/wp-includes/default-constants.php
index 1d9074bda2..f44fb67017 100644
--- a/wp-includes/default-constants.php
+++ b/wp-includes/default-constants.php
@@ -283,13 +283,21 @@ function wp_templating_constants( ) {
 	 */
 	define('STYLESHEETPATH', get_stylesheet_directory());
 
+	/**
+	 * Slug of the default theme for this install.
+	 * Used as the default theme when installing new sites.
+	 * @since 3.0.0
+	 */
+	if ( !defined('WP_DEFAULT_THEME') )
+		define( 'WP_DEFAULT_THEME', 'twentyten' );
+
 	/**
 	 * Slug of the fallback theme for this install.
 	 * Will be used as the fallback if the current theme doesn't exist.
 	 * @since 3.0.0
 	 */
 	if ( !defined('WP_FALLBACK_THEME') )
-		define( 'WP_FALLBACK_THEME', 'twentyten' );
+		define( 'WP_FALLBACK_THEME', WP_DEFAULT_THEME );
 }
 
 ?>