diff --git a/lib/fluent/plugin_helper/http_server/app.rb b/lib/fluent/plugin_helper/http_server/app.rb
index fe8581e1c4..f0456a9b0d 100644
--- a/lib/fluent/plugin_helper/http_server/app.rb
+++ b/lib/fluent/plugin_helper/http_server/app.rb
@@ -71,6 +71,8 @@ def call(request)
                 path
               end
             @router.route!(name, canonical_path, req)
+          ensure
+            request.body&.close
           end
         end
       end
diff --git a/test/plugin_helper/http_server/test_app.rb b/test/plugin_helper/http_server/test_app.rb
index 61ef7b76af..bded72f31f 100644
--- a/test/plugin_helper/http_server/test_app.rb
+++ b/test/plugin_helper/http_server/test_app.rb
@@ -37,7 +37,7 @@ def route!(method, path, _req)
       test 'dispatch correct path' do |method|
         r = DummyRouter.new(method.downcase.to_sym => { '/path/' => 'hi' })
         app = Fluent::PluginHelper::HttpServer::App.new(r, NULL_LOGGER)
-        m = flexmock('request', method: method, path: '/path/')
+        m = flexmock('request', method: method, path: '/path/', body: nil)
         r = app.call(m)
         assert_equal(r.body.read, 'hi')
         assert_equal(r.status, 200)
@@ -46,7 +46,7 @@ def route!(method, path, _req)
       test 'dispatch correct path for head' do |method|
         r = DummyRouter.new(head: { '/path/' => 'hi' })
         app = Fluent::PluginHelper::HttpServer::App.new(r, NULL_LOGGER)
-        m = flexmock('request', method: method, path: '/path')
+        m = flexmock('request', method: method, path: '/path', body: nil)
         r = app.call(m)
         assert_equal(r.body.read, '')
         assert_equal(r.status, 200)
@@ -55,7 +55,7 @@ def route!(method, path, _req)
       test 'if path does not end with `/`' do |method|
         r = DummyRouter.new(head: { '/path/' => 'hi' })
         app = Fluent::PluginHelper::HttpServer::App.new(r, NULL_LOGGER)
-        m = flexmock('request', method: method, path: '/path')
+        m = flexmock('request', method: method, path: '/path', body: nil)
         r = app.call(m)
         assert_equal(r.body.read, '')
         assert_equal(r.status, 200)