diff --git a/app/helpers/settings_helper.rb b/app/helpers/settings_helper.rb
index f6d86a18e8..ba728eb32c 100644
--- a/app/helpers/settings_helper.rb
+++ b/app/helpers/settings_helper.rb
@@ -33,6 +33,7 @@ module SettingsHelper
     'pt-BR': 'Português do Brasil',
     ru: 'Русский',
     sk: 'Slovensky',
+    sl: 'Slovenščina',
     sr: 'Српски',
     'sr-Latn': 'Srpski (latinica)',
     sv: 'Svenska',
diff --git a/app/javascript/mastodon/locales/defaultMessages.json b/app/javascript/mastodon/locales/defaultMessages.json
index 3592918740..49b287928b 100644
--- a/app/javascript/mastodon/locales/defaultMessages.json
+++ b/app/javascript/mastodon/locales/defaultMessages.json
@@ -1857,4 +1857,4 @@
     ],
     "path": "app/javascript/mastodon/features/video/index.json"
   }
-]
+]
\ No newline at end of file
diff --git a/config/application.rb b/config/application.rb
index b4871241a3..729d4dafc0 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -67,6 +67,7 @@ module Mastodon
       :'pt-BR',
       :ru,
       :sk,
+      :sl,
       :sr,
       :'sr-Latn',
       :sv,