diff --git a/homeassistant/components/hassio/http.py b/homeassistant/components/hassio/http.py
index 5bcdb6896cd..84b49af11c2 100644
--- a/homeassistant/components/hassio/http.py
+++ b/homeassistant/components/hassio/http.py
@@ -156,9 +156,8 @@ class HassIOView(HomeAssistantView):
                 # _stored_content_type is only computed once `content_type` is accessed
                 if path == "backups/new/upload":
                     # We need to reuse the full content type that includes the boundary
-                    headers[
-                        CONTENT_TYPE
-                    ] = request._stored_content_type  # pylint: disable=protected-access
+                    # pylint: disable-next=protected-access
+                    headers[CONTENT_TYPE] = request._stored_content_type  # type: ignore[assignment]
 
         try:
             client = await self._websession.request(
diff --git a/homeassistant/helpers/aiohttp_client.py b/homeassistant/helpers/aiohttp_client.py
index ac253d49254..1948d3bca95 100644
--- a/homeassistant/helpers/aiohttp_client.py
+++ b/homeassistant/helpers/aiohttp_client.py
@@ -4,7 +4,6 @@ from __future__ import annotations
 import asyncio
 from collections.abc import Awaitable, Callable
 from contextlib import suppress
-from ssl import SSLContext
 import sys
 from types import MappingProxyType
 from typing import TYPE_CHECKING, Any, cast
@@ -59,6 +58,17 @@ MAXIMUM_CONNECTIONS = 4096
 MAXIMUM_CONNECTIONS_PER_HOST = 100
 
 
+# Overwrite base aiohttp _wait implementation
+# Homeassistant has a custom shutdown wait logic.
+async def _noop_wait(*args: Any, **kwargs: Any) -> None:
+    """Do nothing."""
+    return
+
+
+# pylint: disable-next=protected-access
+web.BaseSite._wait = _noop_wait  # type: ignore[method-assign]
+
+
 class HassClientResponse(aiohttp.ClientResponse):
     """aiohttp.ClientResponse with a json method that uses json_loads by default."""
 
@@ -276,7 +286,7 @@ def _async_get_connector(
         return cast(aiohttp.BaseConnector, hass.data[key])
 
     if verify_ssl:
-        ssl_context: bool | SSLContext = ssl_util.get_default_context()
+        ssl_context = ssl_util.get_default_context()
     else:
         ssl_context = ssl_util.get_default_no_verify_context()
 
diff --git a/homeassistant/package_constraints.txt b/homeassistant/package_constraints.txt
index 799de88f8e0..0a299d50239 100644
--- a/homeassistant/package_constraints.txt
+++ b/homeassistant/package_constraints.txt
@@ -1,5 +1,5 @@
 aiodiscover==1.5.1
-aiohttp==3.8.6
+aiohttp==3.9.0b0
 aiohttp_cors==0.7.0
 astral==2.2
 async-upnp-client==0.36.1
diff --git a/pyproject.toml b/pyproject.toml
index 7badc6be1e4..0bae2c942d7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,7 @@ classifiers = [
 ]
 requires-python = ">=3.11.0"
 dependencies    = [
-    "aiohttp==3.8.6",
+    "aiohttp==3.9.0b0",
     "astral==2.2",
     "attrs==23.1.0",
     "atomicwrites-homeassistant==1.4.1",
diff --git a/requirements.txt b/requirements.txt
index a7ede68c9ec..62c5ab5aede 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 -c homeassistant/package_constraints.txt
 
 # Home Assistant Core
-aiohttp==3.8.6
+aiohttp==3.9.0b0
 astral==2.2
 attrs==23.1.0
 atomicwrites-homeassistant==1.4.1
diff --git a/tests/components/generic/test_camera.py b/tests/components/generic/test_camera.py
index f7f7c390e0d..8bfd0a66dd5 100644
--- a/tests/components/generic/test_camera.py
+++ b/tests/components/generic/test_camera.py
@@ -164,7 +164,7 @@ async def test_limit_refetch(
     hass.states.async_set("sensor.temp", "5")
 
     with pytest.raises(aiohttp.ServerTimeoutError), patch(
-        "async_timeout.timeout", side_effect=asyncio.TimeoutError()
+        "asyncio.timeout", side_effect=asyncio.TimeoutError()
     ):
         resp = await client.get("/api/camera_proxy/camera.config_test")
 
diff --git a/tests/util/test_aiohttp.py b/tests/util/test_aiohttp.py
index 76394b42491..496e6373ba5 100644
--- a/tests/util/test_aiohttp.py
+++ b/tests/util/test_aiohttp.py
@@ -51,7 +51,7 @@ def test_serialize_body_str() -> None:
     assert aiohttp.serialize_response(response) == {
         "status": 201,
         "body": "Hello",
-        "headers": {"Content-Length": "5", "Content-Type": "text/plain; charset=utf-8"},
+        "headers": {"Content-Type": "text/plain; charset=utf-8"},
     }