diff --git a/src/wp-includes/default-filters.php b/src/wp-includes/default-filters.php
index 75a171b4b0..684bea4a37 100644
--- a/src/wp-includes/default-filters.php
+++ b/src/wp-includes/default-filters.php
@@ -431,6 +431,7 @@ add_action( 'init', 'wp_widgets_init', 1 );
 add_action( 'template_redirect', '_wp_admin_bar_init', 0 );
 add_action( 'admin_init', '_wp_admin_bar_init' );
 add_action( 'before_signup_header', '_wp_admin_bar_init' );
+add_action( 'activate_header', '_wp_admin_bar_init' );
 add_action( 'wp_footer', 'wp_admin_bar_render', 1000 );
 add_action( 'in_admin_header', 'wp_admin_bar_render', 0 );