Index: src/wp-includes/taxonomy.php
===================================================================
--- src/wp-includes/taxonomy.php	(revision 39263)
+++ src/wp-includes/taxonomy.php	(working copy)
@@ -388,12 +388,13 @@
 	 * Fires after a taxonomy is registered.
 	 *
 	 * @since 3.3.0
+	 * @since 4.7.0 Converted the `$taxonomy_object` parameter to accept a WP_Taxonomy object.
 	 *
-	 * @param string       $taxonomy    Taxonomy slug.
-	 * @param array|string $object_type Object type or array of object types.
-	 * @param array        $args        Array of taxonomy registration arguments.
+	 * @param string       $taxonomy        Taxonomy slug.
+	 * @param array|string $object_type     Object type or array of object types.
+	 * @param WP_Taxonomy  $taxonomy_object Taxonomy Object.
 	 */
-	do_action( 'registered_taxonomy', $taxonomy, $object_type, $args );
+	do_action( 'registered_taxonomy', $taxonomy, $object_type, $taxonomy_object );
 }
 
 /**