Index: src/wp-includes/pluggable.php
===================================================================
--- src/wp-includes/pluggable.php	(revision 47032)
+++ src/wp-includes/pluggable.php	(working copy)
@@ -1991,7 +1991,7 @@
 
 			wp_mail(
 				$wp_new_user_notification_email_admin['to'],
-				wp_specialchars_decode( sprintf( $wp_new_user_notification_email_admin['subject'], $blogname ) ),
+				html_entity_decode( sprintf( $wp_new_user_notification_email_admin['subject'], $blogname ) ),
 				$wp_new_user_notification_email_admin['message'],
 				$wp_new_user_notification_email_admin['headers']
 			);