diff --git a/CHANGES/4056.feature b/CHANGES/4056.feature
new file mode 100644
index 00000000000..b7fa18b268d
--- /dev/null
+++ b/CHANGES/4056.feature
@@ -0,0 +1 @@
+Compat Python 3.8.
diff --git a/aiohttp/base_protocol.py b/aiohttp/base_protocol.py
index cf4f9dad2ea..331241d9bc0 100644
--- a/aiohttp/base_protocol.py
+++ b/aiohttp/base_protocol.py
@@ -6,7 +6,7 @@
 
 class BaseProtocol(asyncio.Protocol):
     __slots__ = ('_loop', '_paused', '_drain_waiter',
-                 '_connection_lost', 'transport')
+                 '_connection_lost', '_reading_paused', 'transport')
 
     def __init__(self, loop: asyncio.AbstractEventLoop) -> None:
         self._loop = loop  # type: asyncio.AbstractEventLoop
diff --git a/aiohttp/helpers.py b/aiohttp/helpers.py
index ce1d8bfe497..a38a3bb01c9 100644
--- a/aiohttp/helpers.py
+++ b/aiohttp/helpers.py
@@ -53,6 +53,7 @@
 
 PY_36 = sys.version_info >= (3, 6)
 PY_37 = sys.version_info >= (3, 7)
+PY_38 = sys.version_info >= (3, 8)
 
 if not PY_37:
     import idna_ssl
diff --git a/aiohttp/streams.py b/aiohttp/streams.py
index 8b1d020bd6d..352f452a321 100644
--- a/aiohttp/streams.py
+++ b/aiohttp/streams.py
@@ -13,7 +13,6 @@
 except ImportError:
     from typing_extensions import Deque  # noqa
 
-
 __all__ = (
     'EMPTY_PAYLOAD', 'EofStream', 'StreamReader', 'DataQueue',
     'FlowControlDataQueue')
@@ -409,7 +408,7 @@ async def readexactly(self, n: int) -> bytes:
             block = await self.read(n)
             if not block:
                 partial = b''.join(blocks)
-                raise asyncio.streams.IncompleteReadError(
+                raise asyncio.IncompleteReadError(
                     partial, len(partial) + n)
             blocks.append(block)
             n -= len(block)
@@ -514,7 +513,7 @@ async def readchunk(self) -> Tuple[bytes, bool]:
         return (b'', True)
 
     async def readexactly(self, n: int) -> bytes:
-        raise asyncio.streams.IncompleteReadError(b'', n)
+        raise asyncio.IncompleteReadError(b'', n)
 
     def read_nowait(self) -> bytes:
         return b''
diff --git a/aiohttp/test_utils.py b/aiohttp/test_utils.py
index 70323986297..48e10b80d1a 100644
--- a/aiohttp/test_utils.py
+++ b/aiohttp/test_utils.py
@@ -4,6 +4,7 @@
 import contextlib
 import functools
 import gc
+import inspect
 import socket
 import sys
 import unittest
@@ -634,10 +635,11 @@ def make_mocked_request(method: str, path: str,
 def make_mocked_coro(return_value: Any=sentinel,
                      raise_exception: Any=sentinel) -> Any:
     """Creates a coroutine mock."""
-    @asyncio.coroutine
-    def mock_coro(*args: Any, **kwargs: Any) -> Any:
+    async def mock_coro(*args: Any, **kwargs: Any) -> Any:
         if raise_exception is not sentinel:
             raise raise_exception
-        return return_value
+        if not inspect.isawaitable(return_value):
+            return return_value
+        await return_value
 
     return mock.Mock(wraps=mock_coro)
diff --git a/tests/test_client_functional.py b/tests/test_client_functional.py
index 765d2e7debb..374d01809d0 100644
--- a/tests/test_client_functional.py
+++ b/tests/test_client_functional.py
@@ -2420,8 +2420,7 @@ async def handler(request):
         await aiohttp.request('GET', server.make_url('/'))
 
 
-@asyncio.coroutine
-def test_yield_from_in_session_request(aiohttp_client) -> None:
+async def test_yield_from_in_session_request(aiohttp_client) -> None:
     # a test for backward compatibility with yield from syntax
     async def handler(request):
         return web.Response()
@@ -2429,13 +2428,12 @@ async def handler(request):
     app = web.Application()
     app.router.add_get('/', handler)
 
-    client = yield from aiohttp_client(app)
-    resp = yield from client.get('/')
+    client = await aiohttp_client(app)
+    resp = await client.get('/')
     assert resp.status == 200
 
 
-@asyncio.coroutine
-def test_close_context_manager(aiohttp_client) -> None:
+async def test_close_context_manager(aiohttp_client) -> None:
     # a test for backward compatibility with yield from syntax
     async def handler(request):
         return web.Response()
@@ -2443,7 +2441,7 @@ async def handler(request):
     app = web.Application()
     app.router.add_get('/', handler)
 
-    client = yield from aiohttp_client(app)
+    client = await aiohttp_client(app)
     ctx = client.get('/')
     ctx.close()
     assert not ctx._coro.cr_running
diff --git a/tests/test_client_request.py b/tests/test_client_request.py
index 7b5882de29f..df22f8ca494 100644
--- a/tests/test_client_request.py
+++ b/tests/test_client_request.py
@@ -917,7 +917,7 @@ async def gen():
     assert req.headers['TRANSFER-ENCODING'] == 'chunked'
 
     async def throw_exc():
-        await asyncio.sleep(0.01, loop=loop)
+        await asyncio.sleep(0.01)
         fut.set_exception(ValueError)
 
     loop.create_task(throw_exc())
@@ -942,7 +942,7 @@ async def gen():
     inner_exc = ValueError()
 
     async def throw_exc():
-        await asyncio.sleep(0.01, loop=loop)
+        await asyncio.sleep(0.01)
         fut.set_exception(inner_exc)
 
     loop.create_task(throw_exc())
@@ -970,7 +970,7 @@ async def gen():
     assert req.chunked
 
     async def coro():
-        await asyncio.sleep(0.0001, loop=loop)
+        await asyncio.sleep(0.0001)
         req._continue.set_result(1)
 
     loop.create_task(coro())
@@ -989,7 +989,7 @@ async def test_data_continue(loop, buf, conn) -> None:
         expect100=True, loop=loop)
 
     async def coro():
-        await asyncio.sleep(0.0001, loop=loop)
+        await asyncio.sleep(0.0001)
         req._continue.set_result(1)
 
     loop.create_task(coro())
diff --git a/tests/test_client_session.py b/tests/test_client_session.py
index 0a2a51a9594..23a78c8b321 100644
--- a/tests/test_client_session.py
+++ b/tests/test_client_session.py
@@ -17,6 +17,7 @@
 from aiohttp.client_reqrep import ClientRequest
 from aiohttp.connector import BaseConnector, TCPConnector
 from aiohttp.helpers import PY_36
+from aiohttp.test_utils import make_mocked_coro
 
 
 @pytest.fixture
@@ -164,7 +165,11 @@ async def test_merge_headers_with_list_of_tuples_duplicated_names(
 
 
 def test_http_GET(session, params) -> None:
-    with mock.patch("aiohttp.client.ClientSession._request") as patched:
+    # Python 3.8 will auto use mock.AsyncMock, it has different behavior
+    with mock.patch(
+        "aiohttp.client.ClientSession._request",
+        new_callable=mock.MagicMock
+    ) as patched:
         session.get("http://test.example.com",
                     params={"x": 1},
                     **params)
@@ -177,7 +182,10 @@ def test_http_GET(session, params) -> None:
 
 
 def test_http_OPTIONS(session, params) -> None:
-    with mock.patch("aiohttp.client.ClientSession._request") as patched:
+    with mock.patch(
+        "aiohttp.client.ClientSession._request",
+        new_callable=mock.MagicMock
+    ) as patched:
         session.options("http://opt.example.com",
                         params={"x": 2},
                         **params)
@@ -190,7 +198,10 @@ def test_http_OPTIONS(session, params) -> None:
 
 
 def test_http_HEAD(session, params) -> None:
-    with mock.patch("aiohttp.client.ClientSession._request") as patched:
+    with mock.patch(
+        "aiohttp.client.ClientSession._request",
+        new_callable=mock.MagicMock
+    ) as patched:
         session.head("http://head.example.com",
                      params={"x": 2},
                      **params)
@@ -203,7 +214,10 @@ def test_http_HEAD(session, params) -> None:
 
 
 def test_http_POST(session, params) -> None:
-    with mock.patch("aiohttp.client.ClientSession._request") as patched:
+    with mock.patch(
+        "aiohttp.client.ClientSession._request",
+        new_callable=mock.MagicMock
+    ) as patched:
         session.post("http://post.example.com",
                      params={"x": 2},
                      data="Some_data",
@@ -217,7 +231,10 @@ def test_http_POST(session, params) -> None:
 
 
 def test_http_PUT(session, params) -> None:
-    with mock.patch("aiohttp.client.ClientSession._request") as patched:
+    with mock.patch(
+        "aiohttp.client.ClientSession._request",
+        new_callable=mock.MagicMock
+    ) as patched:
         session.put("http://put.example.com",
                     params={"x": 2},
                     data="Some_data",
@@ -231,7 +248,10 @@ def test_http_PUT(session, params) -> None:
 
 
 def test_http_PATCH(session, params) -> None:
-    with mock.patch("aiohttp.client.ClientSession._request") as patched:
+    with mock.patch(
+        "aiohttp.client.ClientSession._request",
+        new_callable=mock.MagicMock
+    ) as patched:
         session.patch("http://patch.example.com",
                       params={"x": 2},
                       data="Some_data",
@@ -245,7 +265,10 @@ def test_http_PATCH(session, params) -> None:
 
 
 def test_http_DELETE(session, params) -> None:
-    with mock.patch("aiohttp.client.ClientSession._request") as patched:
+    with mock.patch(
+        "aiohttp.client.ClientSession._request",
+        new_callable=mock.MagicMock
+    ) as patched:
         session.delete("http://delete.example.com",
                        params={"x": 2},
                        **params)
@@ -491,7 +514,10 @@ async def test_session_default_version(loop) -> None:
 
 
 def test_proxy_str(session, params) -> None:
-    with mock.patch("aiohttp.client.ClientSession._request") as patched:
+    with mock.patch(
+        "aiohttp.client.ClientSession._request",
+        new_callable=mock.MagicMock
+    ) as patched:
         session.get("http://test.example.com",
                     proxy='http://proxy.com',
                     **params)
@@ -515,9 +541,9 @@ async def handler(request):
     body = 'This is request body'
     gathered_req_body = BytesIO()
     gathered_res_body = BytesIO()
-    on_request_start = mock.Mock(side_effect=asyncio.coroutine(mock.Mock()))
-    on_request_redirect = mock.Mock(side_effect=asyncio.coroutine(mock.Mock()))
-    on_request_end = mock.Mock(side_effect=asyncio.coroutine(mock.Mock()))
+    on_request_start = mock.Mock(side_effect=make_mocked_coro(mock.Mock()))
+    on_request_redirect = mock.Mock(side_effect=make_mocked_coro(mock.Mock()))
+    on_request_end = mock.Mock(side_effect=make_mocked_coro(mock.Mock()))
 
     async def on_request_chunk_sent(session, context, params):
         gathered_req_body.write(params.chunk)
@@ -568,9 +594,9 @@ async def on_response_chunk_received(session, context, params):
 
 
 async def test_request_tracing_exception(loop) -> None:
-    on_request_end = mock.Mock(side_effect=asyncio.coroutine(mock.Mock()))
+    on_request_end = mock.Mock(side_effect=make_mocked_coro(mock.Mock()))
     on_request_exception = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
 
     trace_config = aiohttp.TraceConfig()
diff --git a/tests/test_connector.py b/tests/test_connector.py
index 03f5d8bd830..e138beb674b 100644
--- a/tests/test_connector.py
+++ b/tests/test_connector.py
@@ -734,7 +734,7 @@ async def test_tcp_connector_dns_throttle_requests_cancelled_when_close(
         await asyncio.sleep(0)
         await conn.close()
 
-        with pytest.raises(asyncio.futures.CancelledError):
+        with pytest.raises(asyncio.CancelledError):
             await f
 
 
@@ -742,16 +742,16 @@ async def test_tcp_connector_dns_tracing(loop, dns_response) -> None:
     session = mock.Mock()
     trace_config_ctx = mock.Mock()
     on_dns_resolvehost_start = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
     on_dns_resolvehost_end = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
     on_dns_cache_hit = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
     on_dns_cache_miss = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
 
     trace_config = aiohttp.TraceConfig(
@@ -817,10 +817,10 @@ async def test_tcp_connector_dns_tracing_cache_disabled(loop,
     session = mock.Mock()
     trace_config_ctx = mock.Mock()
     on_dns_resolvehost_start = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
     on_dns_resolvehost_end = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
 
     trace_config = aiohttp.TraceConfig(
@@ -891,10 +891,10 @@ async def test_tcp_connector_dns_tracing_throttle_requests(
     session = mock.Mock()
     trace_config_ctx = mock.Mock()
     on_dns_cache_hit = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
     on_dns_cache_miss = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
 
     trace_config = aiohttp.TraceConfig(
@@ -1029,10 +1029,10 @@ async def test_connect_tracing(loop) -> None:
     session = mock.Mock()
     trace_config_ctx = mock.Mock()
     on_connection_create_start = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
     on_connection_create_end = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
 
     trace_config = aiohttp.TraceConfig(
@@ -1421,10 +1421,10 @@ async def test_connect_queued_operation_tracing(loop, key) -> None:
     session = mock.Mock()
     trace_config_ctx = mock.Mock()
     on_connection_queued_start = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
     on_connection_queued_end = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
 
     trace_config = aiohttp.TraceConfig(
@@ -1481,7 +1481,7 @@ async def test_connect_reuseconn_tracing(loop, key) -> None:
     session = mock.Mock()
     trace_config_ctx = mock.Mock()
     on_connection_reuseconn = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock())
+        side_effect=make_mocked_coro(mock.Mock())
     )
 
     trace_config = aiohttp.TraceConfig(
diff --git a/tests/test_helpers.py b/tests/test_helpers.py
index 864498ec3cd..ca6059cb539 100644
--- a/tests/test_helpers.py
+++ b/tests/test_helpers.py
@@ -344,7 +344,7 @@ def test_timer_context_no_task(loop) -> None:
 async def test_weakref_handle(loop) -> None:
     cb = mock.Mock()
     helpers.weakref_handle(cb, 'test', 0.01, loop, False)
-    await asyncio.sleep(0.1, loop=loop)
+    await asyncio.sleep(0.1)
     assert cb.test.called
 
 
@@ -353,7 +353,7 @@ async def test_weakref_handle_weak(loop) -> None:
     helpers.weakref_handle(cb, 'test', 0.01, loop, False)
     del cb
     gc.collect()
-    await asyncio.sleep(0.1, loop=loop)
+    await asyncio.sleep(0.1)
 
 
 def test_ceil_call_later() -> None:
diff --git a/tests/test_proxy.py b/tests/test_proxy.py
index 5a16a300191..da1d6d30f51 100644
--- a/tests/test_proxy.py
+++ b/tests/test_proxy.py
@@ -224,8 +224,7 @@ async def make_conn():
 
         seq = 0
 
-        @asyncio.coroutine
-        def create_connection(*args, **kwargs):
+        async def create_connection(*args, **kwargs):
             nonlocal seq
             seq += 1
 
@@ -275,8 +274,7 @@ async def make_conn():
 
         seq = 0
 
-        @asyncio.coroutine
-        def create_connection(*args, **kwargs):
+        async def create_connection(*args, **kwargs):
             nonlocal seq
             seq += 1
 
diff --git a/tests/test_tracing.py b/tests/test_tracing.py
index 71488afd108..1155f2539dd 100644
--- a/tests/test_tracing.py
+++ b/tests/test_tracing.py
@@ -1,9 +1,9 @@
-import asyncio
 from types import SimpleNamespace
 from unittest.mock import Mock
 
 import pytest
 
+from aiohttp.test_utils import make_mocked_coro
 from aiohttp.tracing import (
     Trace,
     TraceConfig,
@@ -145,7 +145,7 @@ class TestTrace:
     async def test_send(self, signal, params, param_obj) -> None:
         session = Mock()
         trace_request_ctx = Mock()
-        callback = Mock(side_effect=asyncio.coroutine(Mock()))
+        callback = Mock(side_effect=make_mocked_coro(Mock()))
 
         trace_config = TraceConfig()
         getattr(trace_config, "on_%s" % signal).append(callback)
diff --git a/tests/test_web_functional.py b/tests/test_web_functional.py
index 81b60642ce0..7212fd334cb 100644
--- a/tests/test_web_functional.py
+++ b/tests/test_web_functional.py
@@ -20,6 +20,7 @@
     multipart,
     web,
 )
+from aiohttp.test_utils import make_mocked_coro
 
 try:
     import ssl
@@ -1752,17 +1753,17 @@ async def handler(request):
 
 async def test_request_tracing(aiohttp_server) -> None:
 
-    on_request_start = mock.Mock(side_effect=asyncio.coroutine(mock.Mock()))
-    on_request_end = mock.Mock(side_effect=asyncio.coroutine(mock.Mock()))
+    on_request_start = mock.Mock(side_effect=make_mocked_coro(mock.Mock()))
+    on_request_end = mock.Mock(side_effect=make_mocked_coro(mock.Mock()))
     on_dns_resolvehost_start = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock()))
+        side_effect=make_mocked_coro(mock.Mock()))
     on_dns_resolvehost_end = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock()))
-    on_request_redirect = mock.Mock(side_effect=asyncio.coroutine(mock.Mock()))
+        side_effect=make_mocked_coro(mock.Mock()))
+    on_request_redirect = mock.Mock(side_effect=make_mocked_coro(mock.Mock()))
     on_connection_create_start = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock()))
+        side_effect=make_mocked_coro(mock.Mock()))
     on_connection_create_end = mock.Mock(
-        side_effect=asyncio.coroutine(mock.Mock()))
+        side_effect=make_mocked_coro(mock.Mock()))
 
     async def redirector(request):
         raise web.HTTPFound(location=URL('/redirected'))
diff --git a/tests/test_web_protocol.py b/tests/test_web_protocol.py
index 3ea5ad950f0..90da07ebae2 100644
--- a/tests/test_web_protocol.py
+++ b/tests/test_web_protocol.py
@@ -42,9 +42,12 @@ def srv(make_srv, transport):
     srv = make_srv()
     srv.connection_made(transport)
     transport.close.side_effect = partial(srv.connection_lost, None)
-    srv._drain_helper = mock.Mock()
-    srv._drain_helper.side_effect = helpers.noop
-    return srv
+    with mock.patch.object(
+        web.RequestHandler,
+        '_drain_helper',
+        side_effect=helpers.noop
+    ):
+        yield srv
 
 
 @pytest.fixture
@@ -400,19 +403,21 @@ async def test_lingering(srv, transport) -> None:
     async def handle(message, request, writer):
         pass
 
-    srv.handle_request = handle
-    srv.data_received(
-        b'GET / HTTP/1.0\r\n'
-        b'Host: example.com\r\n'
-        b'Content-Length: 3\r\n\r\n')
+    with mock.patch.object(
+        web.RequestHandler, 'handle_request', create=True, new=handle
+    ):
+        srv.data_received(
+            b'GET / HTTP/1.0\r\n'
+            b'Host: example.com\r\n'
+            b'Content-Length: 3\r\n\r\n')
 
-    await asyncio.sleep(0.05)
-    assert not transport.close.called
+        await asyncio.sleep(0.05)
+        assert not transport.close.called
 
-    srv.data_received(b'123')
+        srv.data_received(b'123')
 
-    await asyncio.sleep(0)
-    transport.close.assert_called_with()
+        await asyncio.sleep(0)
+        transport.close.assert_called_with()
 
 
 async def test_lingering_disabled(make_srv,
@@ -491,18 +496,19 @@ async def test_handle_cancel(make_srv, transport) -> None:
     async def handle_request(message, payload, writer):
         await asyncio.sleep(10)
 
-    srv.handle_request = handle_request
-
     async def cancel():
         srv._task_handler.cancel()
 
-    srv.data_received(
-        b'GET / HTTP/1.0\r\n'
-        b'Content-Length: 10\r\n'
-        b'Host: example.com\r\n\r\n')
+    with mock.patch.object(
+        web.RequestHandler, 'handle_request', create=True, new=handle_request
+    ):
+        srv.data_received(
+            b'GET / HTTP/1.0\r\n'
+            b'Content-Length: 10\r\n'
+            b'Host: example.com\r\n\r\n')
 
-    await asyncio.gather(srv._task_handler, cancel())
-    assert log.debug.called
+        await asyncio.gather(srv._task_handler, cancel())
+        assert log.debug.called
 
 
 async def test_handle_cancelled(make_srv, transport) -> None:
@@ -513,7 +519,6 @@ async def test_handle_cancelled(make_srv, transport) -> None:
     srv = make_srv(logger=log)
     srv.connection_made(transport)
 
-    srv.handle_request = mock.Mock()
     # start request_handler task
     await asyncio.sleep(0)
 
@@ -535,29 +540,31 @@ async def test_handle_400(srv, buf, transport) -> None:
 async def test_keep_alive(make_srv, transport, ceil) -> None:
     loop = asyncio.get_event_loop()
     srv = make_srv(keepalive_timeout=0.05)
-    srv.KEEPALIVE_RESCHEDULE_DELAY = 0.1
-    srv.connection_made(transport)
-
-    srv.keep_alive(True)
-    srv.handle_request = mock.Mock()
-    srv.handle_request.return_value = loop.create_future()
-    srv.handle_request.return_value.set_result(1)
-
-    srv.data_received(
-        b'GET / HTTP/1.1\r\n'
-        b'Host: example.com\r\n'
-        b'Content-Length: 0\r\n\r\n')
-
-    waiter = None
-    while waiter is None:
-        await asyncio.sleep(0)
-        waiter = srv._waiter
-    assert srv._keepalive_handle is not None
-    assert not transport.close.called
-
-    await asyncio.sleep(0.2)
-    assert transport.close.called
-    assert waiter.cancelled
+    future = loop.create_future()
+    future.set_result(1)
+
+    with mock.patch.object(
+        web.RequestHandler, 'KEEPALIVE_RESCHEDULE_DELAY', new=0.1
+    ), mock.patch.object(
+        web.RequestHandler, 'handle_request', create=True, return_value=future
+    ):
+        srv.connection_made(transport)
+        srv.keep_alive(True)
+        srv.data_received(
+            b'GET / HTTP/1.1\r\n'
+            b'Host: example.com\r\n'
+            b'Content-Length: 0\r\n\r\n')
+
+        waiter = None
+        while waiter is None:
+            await asyncio.sleep(0)
+            waiter = srv._waiter
+        assert srv._keepalive_handle is not None
+        assert not transport.close.called
+
+        await asyncio.sleep(0.2)
+        assert transport.close.called
+        assert waiter.cancelled
 
 
 async def test_srv_process_request_without_timeout(make_srv,
@@ -634,29 +641,34 @@ async def test_close(srv, transport) -> None:
     srv.connection_made(transport)
     await asyncio.sleep(0)
 
-    srv.handle_request = mock.Mock()
-    srv.handle_request.side_effect = helpers.noop
+    handle_request = mock.Mock()
+    handle_request.side_effect = helpers.noop
+    with mock.patch.object(
+        web.RequestHandler,
+        'handle_request',
+        create=True,
+        new=handle_request
+    ):
+        assert transport is srv.transport
+
+        srv._keepalive = True
+        srv.data_received(
+            b'GET / HTTP/1.1\r\n'
+            b'Host: example.com\r\n'
+            b'Content-Length: 0\r\n\r\n'
+            b'GET / HTTP/1.1\r\n'
+            b'Host: example.com\r\n'
+            b'Content-Length: 0\r\n\r\n')
 
-    assert transport is srv.transport
-
-    srv._keepalive = True
-    srv.data_received(
-        b'GET / HTTP/1.1\r\n'
-        b'Host: example.com\r\n'
-        b'Content-Length: 0\r\n\r\n'
-        b'GET / HTTP/1.1\r\n'
-        b'Host: example.com\r\n'
-        b'Content-Length: 0\r\n\r\n')
-
-    await asyncio.sleep(0.05)
-    assert srv._task_handler
-    assert srv._waiter
+        await asyncio.sleep(0.05)
+        assert srv._task_handler
+        assert srv._waiter
 
-    srv.close()
-    await asyncio.sleep(0)
-    assert srv._task_handler is None
-    assert srv.transport is None
-    assert transport.close.called
+        srv.close()
+        await asyncio.sleep(0)
+        assert srv._task_handler is None
+        assert srv.transport is None
+        assert transport.close.called
 
 
 async def test_pipeline_multiple_messages(
@@ -839,7 +851,10 @@ async def handler(request):
     app.router.add_route('POST', '/', handler)
     server = await aiohttp_server(app, logger=logger)
 
-    _, writer = await asyncio.open_connection('127.0.0.1', server.port)
+    if helpers.PY_38:
+        writer = await asyncio.connect('127.0.0.1', server.port)
+    else:
+        _, writer = await asyncio.open_connection('127.0.0.1', server.port)
     writer.write("""POST / HTTP/1.1\r
 Connection: keep-alive\r
 Content-Length: 10\r