diff --git a/wp-includes/kses.php b/wp-includes/kses.php
index a996b86a91..5310f0caf9 100644
--- a/wp-includes/kses.php
+++ b/wp-includes/kses.php
@@ -252,6 +252,12 @@ if ( ! CUSTOM_TAGS ) {
 			'align' => true,
 			'value' => true,
 		),
+		'main'        => array(
+			'align'    => true,
+			'dir'      => true,
+			'lang'     => true,
+			'xml:lang' => true,
+		),
 		'map'        => array(
 			'name' => true,
 		),
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 11d2e265fd..c386004274 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.8-alpha-50986';
+$wp_version = '5.8-alpha-50987';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.