diff --git a/app/controllers/fluentd/settings/histories_controller.rb b/app/controllers/fluentd/settings/histories_controller.rb
index 6704e3d..e73a18f 100644
--- a/app/controllers/fluentd/settings/histories_controller.rb
+++ b/app/controllers/fluentd/settings/histories_controller.rb
@@ -5,7 +5,7 @@ class Fluentd::Settings::HistoriesController < ApplicationController
 
   def index
     @backup_files = @fluentd.agent.backup_files_in_new_order.map do |file_path|
-      Fluentd::Setting::BackupFile.new(file_path: file_path)
+      Fluentd::Setting::BackupFile.new(file_path)
     end
   end
 
@@ -21,11 +21,6 @@ class Fluentd::Settings::HistoriesController < ApplicationController
 
   def find_backup_file
     #Do not use BackupFile.new(params[:id]) because params[:id] can be any path.
-    @backup_file = Fluentd::Setting::BackupFile.find_by_file_id(
-      {
-        backup_dir: @fluentd.agent.config_backup_dir,
-        file_id: params[:id]
-      }
-    )
+    @backup_file = Fluentd::Setting::BackupFile.find_by_file_id(@fluentd.agent.config_backup_dir, params[:id])
   end
 end
diff --git a/app/controllers/fluentd/settings_controller.rb b/app/controllers/fluentd/settings_controller.rb
index c193083..27776d5 100644
--- a/app/controllers/fluentd/settings_controller.rb
+++ b/app/controllers/fluentd/settings_controller.rb
@@ -7,7 +7,7 @@ class Fluentd::SettingsController < ApplicationController
 
   def show
     @backup_files = @fluentd.agent.backup_files_in_new_order[0..4].map do |file_path|
-      Fluentd::Setting::BackupFile.new(file_path: file_path)
+      Fluentd::Setting::BackupFile.new(file_path)
     end
   end
 
diff --git a/app/models/fluentd/setting/backup_file.rb b/app/models/fluentd/setting/backup_file.rb
index 8e39906..4005aa3 100644
--- a/app/models/fluentd/setting/backup_file.rb
+++ b/app/models/fluentd/setting/backup_file.rb
@@ -3,14 +3,14 @@ class Fluentd
     class BackupFile
       attr_accessor :file_path
 
-      def self.find_by_file_id(backup_dir: , file_id: )
+      def self.find_by_file_id(backup_dir, file_id)
         file_path = Pathname.new(backup_dir).join("#{file_id}.conf")
         raise "No suce file #{file_path}" unless File.exist?(file_path)
 
-        new(file_path: file_path)
+        new(file_path)
       end
 
-      def initialize(file_path: nil)
+      def initialize(file_path)
         @file_path = file_path
       end
 
@@ -31,6 +31,7 @@ class Fluentd
       end
 
       private
+
       def with_file
         return nil unless file_path && File.exist?(file_path)
         yield
diff --git a/spec/features/fluentd/setting/hisotries_spec.rb b/spec/features/fluentd/setting/hisotries_spec.rb
index d2faa32..9ae1db7 100644
--- a/spec/features/fluentd/setting/hisotries_spec.rb
+++ b/spec/features/fluentd/setting/hisotries_spec.rb
@@ -26,7 +26,8 @@ describe "histories", stub: :daemon do
   end
 
   describe 'show' do
-     let(:last_backup_file) { Fluentd::Setting::BackupFile.new(file_path: daemon.agent.backup_files_in_new_order.first) }
+    let(:last_backup_file) { Fluentd::Setting::BackupFile.new(daemon.agent.backup_files_in_new_order.first) }
+
     before do
       visit "/daemon/setting/histories/#{last_backup_file.file_id}"
     end