diff --git a/apps/api/app/controllers/files_controller.rb b/apps/api/app/controllers/files_controller.rb
index c6d04f6..8d557d7 100644
--- a/apps/api/app/controllers/files_controller.rb
+++ b/apps/api/app/controllers/files_controller.rb
@@ -7,8 +7,9 @@ class FilesController < ApplicationController
     full_path = BASE_PATH.join(requested)
 
     if File.directory?(full_path)
-      return redirect_to(request.path + "/", status: :moved_permanently) unless request.path.end_with?("/")
-      full_path = full_path.join('index.html')
+      index_path = full_path.join('index.html')
+      return head(:not_found) unless File.file?(index_path)
+      return redirect_to("/file/#{requested.chomp('/')}/index.html", status: :moved_permanently)
     end
 
     if File.file?(full_path)