diff --git a/wp-includes/update.php b/wp-includes/update.php
index ac9c31fac..1f37ab237 100644
--- a/wp-includes/update.php
+++ b/wp-includes/update.php
@@ -323,6 +323,7 @@ add_action( 'wp_update_plugins', 'wp_update_plugins' );
 
 add_action( 'load-themes.php', 'wp_update_themes' );
 add_action( 'load-update.php', 'wp_update_themes' );
+add_action( 'load-update-core.php', 'wp_update_themes' );
 add_action( 'admin_init', '_maybe_update_themes' );
 add_action( 'wp_update_themes', 'wp_update_themes' );