diff --git a/src/wp-includes/default-filters.php b/src/wp-includes/default-filters.php
index c28594fdca..e7027a52ce 100644
--- a/src/wp-includes/default-filters.php
+++ b/src/wp-includes/default-filters.php
@@ -175,6 +175,7 @@ add_filter( 'option_blog_charset',      '_canonical_charset'                  );
 add_filter( 'option_home',              '_config_wp_home'                     );
 add_filter( 'option_siteurl',           '_config_wp_siteurl'                  );
 add_filter( 'tiny_mce_before_init',     '_mce_set_direction'                  );
+add_filter( 'teeny_mce_before_init',    '_mce_set_direction'                  );
 add_filter( 'pre_kses',                 'wp_pre_kses_less_than'               );
 add_filter( 'sanitize_title',           'sanitize_title_with_dashes',   10, 3 );
 add_action( 'check_comment_flood',      'check_comment_flood_db',       10, 3 );