Index: src/wp-includes/pluggable.php
===================================================================
--- src/wp-includes/pluggable.php	(revision 37021)
+++ src/wp-includes/pluggable.php	(working copy)
@@ -1115,7 +1115,7 @@
 
 	if ( $die && false === $result ) {
 		if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
-			wp_die( -1 );
+			wp_die( -1, 403 );
 		} else {
 			die( '-1' );
 		}
Index: src/wp-includes/functions.php
===================================================================
--- src/wp-includes/functions.php	(revision 37021)
+++ src/wp-includes/functions.php	(working copy)
@@ -2812,9 +2812,19 @@
  * @since 3.4.0
  * @access private
  *
- * @param string $message Optional. Response to print. Default empty.
- */
-function _ajax_wp_die_handler( $message = '' ) {
+ * @param string       $message Error message.
+ * @param string       $title   Optional. Error title. Default empty.
+ * @param string|array $args    Optional. Arguments to control behavior. Default empty array.
+ */
+function _ajax_wp_die_handler( $message, $title = '', $args = array() ) {
+	$defaults = array(
+		'response' => 200,
+	);
+	$r = wp_parse_args( $args, $defaults );
+
+	if ( ! headers_sent() ) {
+		status_header( $r['response'] );
+	}
 	if ( is_scalar( $message ) )
 		die( (string) $message );
 	die( '0' );