diff --git a/app/tutorial.rb b/app/tutorial.rb
index cbef80bf..2ffe69bd 100644
--- a/app/tutorial.rb
+++ b/app/tutorial.rb
@@ -24,7 +24,7 @@ end
 
 get '/tutorial/:section/?' do
   require_login
-  not_found unless %w{html css js}.include?(params[:section])
+  not_found unless %w{html}.include?(params[:section])
   redirect "/tutorial/#{params[:section]}/1"
 end
 
@@ -32,7 +32,7 @@ get '/tutorial/:section/:page/?' do
   require_login
   @page = params[:page]
   not_found unless @page.match?(/\A[1-9]\z|\A10\z/)
-  not_found unless %w{html css js}.include?(params[:section])
+  not_found unless %w{html}.include?(params[:section])
 
   @section = params[:section]