diff --git a/src/wp-includes/post.php b/src/wp-includes/post.php
index 9f02fff09d..5377f4eaee 100644
--- a/src/wp-includes/post.php
+++ b/src/wp-includes/post.php
@@ -356,7 +356,7 @@ function create_initial_post_types() {
 			'public'                => false,
 			'_builtin'              => true, /* internal use only. don't use this when registering your own post type. */
 			'has_archive'           => false,
-			'show_ui'               => wp_is_block_theme(),
+			'show_ui'               => false,
 			'show_in_menu'          => false,
 			'show_in_rest'          => true,
 			'rewrite'               => false,
@@ -416,7 +416,7 @@ function create_initial_post_types() {
 			'public'                => false,
 			'_builtin'              => true, /* internal use only. don't use this when registering your own post type. */
 			'has_archive'           => false,
-			'show_ui'               => wp_is_block_theme(),
+			'show_ui'               => false,
 			'show_in_menu'          => false,
 			'show_in_rest'          => true,
 			'rewrite'               => false,