diff --git a/cookbooks/base/default.rb b/cookbooks/base/default.rb
index 97ad48e..1704b7a 100644
--- a/cookbooks/base/default.rb
+++ b/cookbooks/base/default.rb
@@ -54,17 +54,18 @@ include_recipe './fortune.rb'
 # timezone configurations:
 include_recipe './timezone.rb'
 
-# ntp configurations:
-include_recipe './ntp.rb'
-
 # kernel configurations:
 include_recipe './kernel.rb'
 
 # Install mc command:
 include_recipe './mc.rb'
 
-# unnecessary configurations:
+# recipes for Ubuntu 16.04
 if node['platform_version'].to_f == 16.04
+  # ntp configurations
+  include_recipe './ntp.rb'
+
+  # misc recipe
   include_recipe './unnecessary.rb'
 end
 
diff --git a/cookbooks/base/ntp.rb b/cookbooks/base/ntp.rb
index aaf520d..be36310 100644
--- a/cookbooks/base/ntp.rb
+++ b/cookbooks/base/ntp.rb
@@ -1,18 +1,13 @@
-case run_command('grep VERSION_ID /etc/os-release | awk -F\" \'{print $2}\'').stdout.chomp
-when "18.04"
-  # do nothing
-else
-  package 'ntp'
+package 'ntp'
 
-  remote_file '/etc/ntp.conf' do
-    owner 'root'
-    group 'root'
-    mode '644'
+remote_file '/etc/ntp.conf' do
+  owner 'root'
+  group 'root'
+  mode '644'
 
-    notifies :restart, 'service[ntp]'
-  end
-
-  service 'ntp' do
-    action :nothing
-  end
+  notifies :restart, 'service[ntp]'
+end
+
+service 'ntp' do
+  action :nothing
 end