diff --git a/proxy.py b/proxy.py
index 6631abcc..aaad662b 100755
--- a/proxy.py
+++ b/proxy.py
@@ -970,6 +970,7 @@ class Threadless(multiprocessing.Process):
             **self.kwargs)
         try:
             self.works[fileno].initialize()
+            os.close(fileno)
         except ssl.SSLError as e:
             logger.exception('ssl.SSLError', exc_info=e)
             self.cleanup(fileno)
@@ -1119,7 +1120,6 @@ class Acceptor(multiprocessing.Process):
             family=self.family,
             type=socket.SOCK_STREAM
         )
-        os.close(fileno)
         try:
             self.selector.register(self.sock, selectors.EVENT_READ)
             self.start_threadless_process()
@@ -2524,7 +2524,6 @@ class ProtocolHandler(threading.Thread, ThreadlessWork):
         conn = socket.fromfd(
             fileno, family=socket.AF_INET if self.config.hostname.version == 4 else socket.AF_INET6,
             type=socket.SOCK_STREAM)
-        os.close(fileno)
         return conn
 
     def optionally_wrap_socket(
diff --git a/tests.py b/tests.py
index b4d0e864..1445cb90 100644
--- a/tests.py
+++ b/tests.py
@@ -294,7 +294,6 @@ class TestWorker(unittest.TestCase):
             mock_protocol_handler,
             config=self.protocol_config)
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     @mock.patch('proxy.recv_handle')
@@ -302,8 +301,7 @@ class TestWorker(unittest.TestCase):
             self,
             mock_recv_handle: mock.Mock,
             mock_fromfd: mock.Mock,
-            mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            mock_selector: mock.Mock) -> None:
         fileno = 10
         conn = mock.MagicMock()
         addr = mock.MagicMock()
@@ -319,7 +317,6 @@ class TestWorker(unittest.TestCase):
         sock.accept.assert_not_called()
         self.mock_protocol_handler.assert_not_called()
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     @mock.patch('proxy.recv_handle')
@@ -327,8 +324,7 @@ class TestWorker(unittest.TestCase):
             self,
             mock_recv_handle: mock.Mock,
             mock_fromfd: mock.Mock,
-            mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            mock_selector: mock.Mock) -> None:
         fileno = 10
         conn = mock.MagicMock()
         addr = mock.MagicMock()
@@ -344,7 +340,6 @@ class TestWorker(unittest.TestCase):
 
         self.mock_protocol_handler.assert_not_called()
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     @mock.patch('proxy.recv_handle')
@@ -352,8 +347,7 @@ class TestWorker(unittest.TestCase):
             self,
             mock_recv_handle: mock.Mock,
             mock_fromfd: mock.Mock,
-            mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            mock_selector: mock.Mock) -> None:
         fileno = 10
         conn = mock.MagicMock()
         addr = mock.MagicMock()
@@ -1008,13 +1002,11 @@ class TestWebsocketClient(unittest.TestCase):
 
 class TestHttpProtocolHandler(unittest.TestCase):
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     def setUp(self,
               mock_fromfd: mock.Mock,
-              mock_selector: mock.Mock,
-              mock_os_close: mock.Mock) -> None:
+              mock_selector: mock.Mock) -> None:
         self.fileno = 10
         self._addr = ('127.0.0.1', 54382)
         self._conn = mock_fromfd.return_value
@@ -1027,7 +1019,6 @@ class TestHttpProtocolHandler(unittest.TestCase):
         self.mock_selector = mock_selector
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=self.config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
 
     @mock.patch('proxy.TcpServerConnection')
@@ -1141,14 +1132,12 @@ class TestHttpProtocolHandler(unittest.TestCase):
         self.proxy.run_once()
         self.assertEqual(self.proxy.client.buffer, proxy.ProxyConnectionFailed.RESPONSE_PKT)
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     def test_proxy_authentication_failed(
             self,
             mock_fromfd: mock.Mock,
-            mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            mock_selector: mock.Mock) -> None:
         self._conn = mock_fromfd.return_value
         self.mock_selector_for_client_read(mock_selector)
         config = proxy.ProtocolConfig(
@@ -1158,7 +1147,6 @@ class TestHttpProtocolHandler(unittest.TestCase):
             b'proxy.HttpProxyPlugin,proxy.HttpWebServerPlugin')
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
         self._conn.recv.return_value = proxy.CRLF.join([
             b'GET http://abhinavsingh.com HTTP/1.1',
@@ -1170,15 +1158,13 @@ class TestHttpProtocolHandler(unittest.TestCase):
             self.proxy.client.buffer,
             proxy.ProxyAuthenticationFailed.RESPONSE_PKT)
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     @mock.patch('proxy.TcpServerConnection')
     def test_authenticated_proxy_http_get(
             self, mock_server_connection: mock.Mock,
             mock_fromfd: mock.Mock,
-            mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            mock_selector: mock.Mock) -> None:
         self._conn = mock_fromfd.return_value
         self.mock_selector_for_client_read(mock_selector)
 
@@ -1194,7 +1180,6 @@ class TestHttpProtocolHandler(unittest.TestCase):
 
         self.proxy = proxy.ProtocolHandler(
             self.fileno, addr=self._addr, config=config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
         assert self.http_server_port is not None
 
@@ -1221,15 +1206,13 @@ class TestHttpProtocolHandler(unittest.TestCase):
         ])
         self.assert_data_queued(mock_server_connection, server)
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     @mock.patch('proxy.TcpServerConnection')
     def test_authenticated_proxy_http_tunnel(
             self, mock_server_connection: mock.Mock,
             mock_fromfd: mock.Mock,
-            mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            mock_selector: mock.Mock) -> None:
         server = mock_server_connection.return_value
         server.connect.return_value = True
         server.buffer_size.return_value = 0
@@ -1244,7 +1227,6 @@ class TestHttpProtocolHandler(unittest.TestCase):
 
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
 
         assert self.http_server_port is not None
@@ -1338,10 +1320,9 @@ class TestHttpProtocolHandler(unittest.TestCase):
 
 class TestWebServerPlugin(unittest.TestCase):
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
-    def setUp(self, mock_fromfd: mock.Mock, mock_selector: mock.Mock, mock_os_close: mock.Mock) -> None:
+    def setUp(self, mock_fromfd: mock.Mock, mock_selector: mock.Mock) -> None:
         self.fileno = 10
         self._addr = ('127.0.0.1', 54382)
         self._conn = mock_fromfd.return_value
@@ -1351,20 +1332,16 @@ class TestWebServerPlugin(unittest.TestCase):
             b'proxy.HttpProxyPlugin,proxy.HttpWebServerPlugin')
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=self.config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     def test_pac_file_served_from_disk(
-            self, mock_fromfd: mock.Mock, mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            self, mock_fromfd: mock.Mock, mock_selector: mock.Mock) -> None:
         pac_file = 'proxy.pac'
         self._conn = mock_fromfd.return_value
         self.mock_selector_for_client_read(mock_selector)
         self.init_and_make_pac_file_request(pac_file)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.run_once()
         self.assertEqual(
             self.proxy.request.state,
@@ -1377,17 +1354,14 @@ class TestWebServerPlugin(unittest.TestCase):
                 }, body=f.read()
             ))
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     def test_pac_file_served_from_buffer(
-            self, mock_fromfd: mock.Mock, mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            self, mock_fromfd: mock.Mock, mock_selector: mock.Mock) -> None:
         self._conn = mock_fromfd.return_value
         self.mock_selector_for_client_read(mock_selector)
         pac_file_content = b'function FindProxyForURL(url, host) { return "PROXY localhost:8899; DIRECT"; }'
         self.init_and_make_pac_file_request(proxy.text_(pac_file_content))
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.run_once()
         self.assertEqual(
             self.proxy.request.state,
@@ -1399,12 +1373,10 @@ class TestWebServerPlugin(unittest.TestCase):
             }, body=pac_file_content
         ))
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     def test_default_web_server_returns_404(
-            self, mock_fromfd: mock.Mock, mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            self, mock_fromfd: mock.Mock, mock_selector: mock.Mock) -> None:
         self._conn = mock_fromfd.return_value
         mock_selector.return_value.select.return_value = [(
             selectors.SelectorKey(
@@ -1417,7 +1389,6 @@ class TestWebServerPlugin(unittest.TestCase):
             b'proxy.HttpProxyPlugin,proxy.HttpWebServerPlugin')
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
         self._conn.recv.return_value = proxy.CRLF.join([
             b'GET /hello HTTP/1.1',
@@ -1431,12 +1402,10 @@ class TestWebServerPlugin(unittest.TestCase):
             self.proxy.client.buffer,
             proxy.HttpWebServerPlugin.DEFAULT_404_RESPONSE)
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     def test_static_web_server_serves(
-            self, mock_fromfd: mock.Mock, mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            self, mock_fromfd: mock.Mock, mock_selector: mock.Mock) -> None:
         # Setup a static directory
         static_server_dir = os.path.join(tempfile.gettempdir(), 'static')
         index_file_path = os.path.join(static_server_dir, 'index.html')
@@ -1488,14 +1457,12 @@ class TestWebServerPlugin(unittest.TestCase):
             body=html_file_content
         ))
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     def test_static_web_server_serves_404(
             self,
             mock_fromfd: mock.Mock,
-            mock_selector: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            mock_selector: mock.Mock) -> None:
         self._conn = mock_fromfd.return_value
         self._conn.recv.return_value = proxy.build_http_request(b'GET', b'/not-found.html')
 
@@ -1517,7 +1484,6 @@ class TestWebServerPlugin(unittest.TestCase):
 
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
 
         self.proxy.run_once()
@@ -1528,17 +1494,15 @@ class TestWebServerPlugin(unittest.TestCase):
         self.assertEqual(self._conn.send.call_args[0][0],
                          proxy.HttpWebServerPlugin.DEFAULT_404_RESPONSE)
 
-    @mock.patch('os.close')
     @mock.patch('socket.fromfd')
     def test_on_client_connection_called_on_teardown(
-            self, mock_fromfd: mock.Mock, mock_os_close: mock.Mock) -> None:
+            self, mock_fromfd: mock.Mock) -> None:
         config = proxy.ProtocolConfig()
         plugin = mock.MagicMock()
         config.plugins = {b'ProtocolHandlerPlugin': [plugin]}
         self._conn = mock_fromfd.return_value
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
         plugin.assert_called()
         with mock.patch.object(self.proxy, 'run_once') as mock_run_once:
@@ -1570,13 +1534,11 @@ class TestWebServerPlugin(unittest.TestCase):
 
 class TestHttpProxyPlugin(unittest.TestCase):
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     def setUp(self,
               mock_fromfd: mock.Mock,
-              mock_selector: mock.Mock,
-              mock_os_close: mock.Mock) -> None:
+              mock_selector: mock.Mock) -> None:
         self.mock_fromfd = mock_fromfd
         self.mock_selector = mock_selector
 
@@ -1591,7 +1553,6 @@ class TestHttpProxyPlugin(unittest.TestCase):
         self._conn = mock_fromfd.return_value
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=self.config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
 
     def test_proxy_plugin_initialized(self) -> None:
@@ -1646,13 +1607,11 @@ class TestHttpProxyPlugin(unittest.TestCase):
 
 class TestHttpProxyPluginExamples(unittest.TestCase):
 
-    @mock.patch('os.close')
     @mock.patch('selectors.DefaultSelector')
     @mock.patch('socket.fromfd')
     def setUp(self,
               mock_fromfd: mock.Mock,
-              mock_selector: mock.Mock,
-              mock_os_close: mock.Mock) -> None:
+              mock_selector: mock.Mock) -> None:
         self.fileno = 10
         self._addr = ('127.0.0.1', 54382)
         self.config = proxy.ProtocolConfig()
@@ -1670,7 +1629,6 @@ class TestHttpProxyPluginExamples(unittest.TestCase):
         self._conn = mock_fromfd.return_value
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=self.config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
 
     @mock.patch('proxy.TcpServerConnection')
@@ -1871,7 +1829,6 @@ class TestHttpProxyPluginExamples(unittest.TestCase):
 
 class TestHttpProxyTlsInterception(unittest.TestCase):
 
-    @mock.patch('os.close')
     @mock.patch('ssl.wrap_socket')
     @mock.patch('ssl.create_default_context')
     @mock.patch('proxy.TcpServerConnection')
@@ -1885,8 +1842,7 @@ class TestHttpProxyTlsInterception(unittest.TestCase):
             mock_popen: mock.Mock,
             mock_server_conn: mock.Mock,
             mock_ssl_context: mock.Mock,
-            mock_ssl_wrap: mock.Mock,
-            mock_os_close: mock.Mock) -> None:
+            mock_ssl_wrap: mock.Mock) -> None:
         host, port = uuid.uuid4().hex, 443
         netloc = '{0}:{1}'.format(host, port)
 
@@ -1926,7 +1882,6 @@ class TestHttpProxyTlsInterception(unittest.TestCase):
         self._conn = mock_fromfd.return_value
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=self.config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
 
         self.plugin.assert_called()
@@ -2005,7 +1960,6 @@ class TestHttpProxyTlsInterception(unittest.TestCase):
 
 class TestHttpProxyPluginExamplesWithTlsInterception(unittest.TestCase):
 
-    @mock.patch('os.close')
     @mock.patch('ssl.wrap_socket')
     @mock.patch('ssl.create_default_context')
     @mock.patch('proxy.TcpServerConnection')
@@ -2018,8 +1972,7 @@ class TestHttpProxyPluginExamplesWithTlsInterception(unittest.TestCase):
               mock_popen: mock.Mock,
               mock_server_conn: mock.Mock,
               mock_ssl_context: mock.Mock,
-              mock_ssl_wrap: mock.Mock,
-              mock_os_close: mock.Mock) -> None:
+              mock_ssl_wrap: mock.Mock) -> None:
         self.mock_fromfd = mock_fromfd
         self.mock_selector = mock_selector
         self.mock_popen = mock_popen
@@ -2045,7 +1998,6 @@ class TestHttpProxyPluginExamplesWithTlsInterception(unittest.TestCase):
         mock_fromfd.return_value = self._conn
         self.proxy = proxy.ProtocolHandler(
             self.fileno, self._addr, config=self.config)
-        mock_os_close.assert_called_with(self.fileno)
         self.proxy.initialize()
 
         self.server = self.mock_server_conn.return_value