diff --git a/config/application.rb b/config/application.rb
index dc937ca0eb0..a3991639c58 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -25,7 +25,7 @@ module Mastodon
     # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
     # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
 
-    config.i18n.available_locales = [:en, :de, :es, :pt, :fr, :hu, :uk, 'zh-CN', :fi, :eo, :ru]
+    config.i18n.available_locales = [:en, :de, :es, :pt, :fr, :hu, :uk, 'zh-CN', :fi, :eo, :ru, :ja]
 
     config.i18n.default_locale    = :en