diff -r 0ddba0abab49 Lib/http/server.py
--- a/Lib/http/server.py	Thu Jun 02 10:13:47 2016 +0000
+++ b/Lib/http/server.py	Thu Jun 02 16:54:10 2016 -0700
@@ -456,13 +456,20 @@
         self.send_response(code, message)
         self.send_header("Content-Type", self.error_content_type)
         self.send_header('Connection', 'close')
-        self.send_header('Content-Length', int(len(body)))
+        if code not in (HTTPStatus.NO_CONTENT, HTTPStatus.RESET_CONTENT):
+            # RFC7230: 3.3.2. You can't send Content-Length for 204(NO_CONTENT)
+            # RFC7231: 6.3.6. Content-Length is not a required field and sending
+            #                 blank line and closing connection immediately is a
+            #                 correct behavior described in the RFC.
+            self.send_header('Content-Length', int(len(body)))
         self.end_headers()
 
         if (self.command != 'HEAD' and
                 code >= 200 and
                 code not in (
-                    HTTPStatus.NO_CONTENT, HTTPStatus.NOT_MODIFIED)):
+                    HTTPStatus.NO_CONTENT,
+                    HTTPStatus.RESET_CONTENT,
+                    HTTPStatus.NOT_MODIFIED)):
             self.wfile.write(body)
 
     def send_response(self, code, message=None):
diff -r 0ddba0abab49 Lib/test/test_httpservers.py
--- a/Lib/test/test_httpservers.py	Thu Jun 02 10:13:47 2016 +0000
+++ b/Lib/test/test_httpservers.py	Thu Jun 02 16:54:10 2016 -0700
@@ -116,6 +116,18 @@
             body = self.headers['x-special-incoming'].encode('utf-8')
             self.wfile.write(body)
 
+        def do_NOCONTENT_VIA_SEND_ERROR(self):
+            # RFC7231: 6.3.5
+            # In most cases, NO_CONTENT should be sent via
+            # send_response() as this is actually not an error.
+            self.send_error(HTTPStatus.NO_CONTENT)
+
+        def do_RESETCONTENT_VIA_SEND_ERROR(self):
+            # RFC7231: 6.3.6
+            # In most cases, RESET_CONTENT should be sent via
+            # send_response() as this is actually not an error.
+            self.send_error(HTTPStatus.RESET_CONTENT)
+
     def setUp(self):
         BaseTestCase.setUp(self)
         self.con = http.client.HTTPConnection(self.HOST, self.PORT)
@@ -237,6 +249,29 @@
         data = res.read()
         self.assertEqual(int(res.getheader('Content-Length')), len(data))
 
+    def test_no_content_via_send_error(self):
+        # RFC7230: 3.3.2 states that Content-Length must not be specified
+        # in response message with 204(NO_CONTENT).
+        self.con.request('NOCONTENT_VIA_SEND_ERROR', '/')
+        res = self.con.getresponse()
+        self.assertEqual(HTTPStatus.NO_CONTENT, res.status)
+        self.assertEqual(None, res.getheader('Content-Length'))
+
+        data = res.read()
+        self.assertEqual(b'', data)
+
+    def test_reset_content(self):
+        # RFC7231: 6.3.6 There are 3 ways to handle 205(RESET_CONTENT)
+        # In this implementation, we'll expect option c) in RFC where
+        # it'll receive empty line in the body.
+        self.con.request('RESETCONTENT_VIA_SEND_ERROR', '/')
+        res = self.con.getresponse()
+        self.assertEqual(HTTPStatus.RESET_CONTENT, res.status)
+        self.assertEqual(None, res.getheader('Content-Length'))
+
+        data = res.read()
+        self.assertEqual(b'', data)
+
 
 class RequestHandlerLoggingTestCase(BaseTestCase):
     class request_handler(BaseHTTPRequestHandler):