diff --git a/lib/fluent/plugin_helper/http_server/router.rb b/lib/fluent/plugin_helper/http_server/router.rb
index 069d3aa0b8..1ff64cef50 100644
--- a/lib/fluent/plugin_helper/http_server/router.rb
+++ b/lib/fluent/plugin_helper/http_server/router.rb
@@ -22,7 +22,7 @@ module HttpServer
       class Router
         class NotFoundApp
           def self.call(req)
-            [404, { 'Content-Type' => 'text/plain' }, "404 Not Found: #{req.path}\n"]
+            [404, { 'Content-Type' => 'text/plain' }, "404 Not Found\n"]
           end
         end
 
diff --git a/test/plugin_helper/http_server/test_route.rb b/test/plugin_helper/http_server/test_route.rb
index 83656fc5d9..ec2b81bf03 100644
--- a/test/plugin_helper/http_server/test_route.rb
+++ b/test/plugin_helper/http_server/test_route.rb
@@ -20,7 +20,7 @@ class HttpHelperRouterTest < Test::Unit::TestCase
       test 'use default app if path is not found' do
         router = Fluent::PluginHelper::HttpServer::Router.new
         req = flexmock('request', path: 'path/')
-        assert_equal(router.route!(:get, '/path/', req), [404, { 'Content-Type' => 'text/plain' }, "404 Not Found: #{req.path}\n"])
+        assert_equal(router.route!(:get, '/path/', req), [404, { 'Content-Type' => 'text/plain' }, "404 Not Found\n"])
       end
 
       test 'default app is configurable' do