diff --git a/wp-includes/load.php b/wp-includes/load.php
index a29eed1002..71b3a4a3e7 100644
--- a/wp-includes/load.php
+++ b/wp-includes/load.php
@@ -418,7 +418,12 @@ function require_wp_db() {
 		return;
 	}
 
-	$wpdb = new wpdb( DB_USER, DB_PASSWORD, DB_NAME, DB_HOST );
+	$dbuser     = defined( 'DB_USER' ) ? DB_USER : '';
+	$dbpassword = defined( 'DB_PASSWORD' ) ? DB_PASSWORD : '';
+	$dbname     = defined( 'DB_NAME' ) ? DB_NAME : '';
+	$dbhost     = defined( 'DB_HOST' ) ? DB_HOST : '';
+
+	$wpdb = new wpdb( $dbuser, $dbpassword, $dbname, $dbhost );
 }
 
 /**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 885561b00d..e937edfdae 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-42700';
+$wp_version = '5.0-alpha-42701';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.