diff --git a/wp-admin/includes/post.php b/wp-admin/includes/post.php
index 1f9465564654..37b9239b2540 100644
--- a/wp-admin/includes/post.php
+++ b/wp-admin/includes/post.php
@@ -2206,6 +2206,11 @@ function get_block_categories( $post ) {
 			'title' => _x( 'Widgets', 'block category' ),
 			'icon'  => null,
 		),
+		array(
+			'slug'  => 'theme',
+			'title' => _x( 'Theme', 'block category' ),
+			'icon'  => null,
+		),
 		array(
 			'slug'  => 'embed',
 			'title' => _x( 'Embeds', 'block category' ),
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 7af6b061a53f..c87c81ea7ad3 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.8-alpha-50563';
+$wp_version = '5.8-alpha-50564';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.