diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7cf523801e..88b80e87a9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,7 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: [3.8, 3.9, "3.10", 3.11]
+        python-version: [3.8, 3.9, "3.10", 3.11, 3.12]
 
     runs-on: ${{ matrix.os }}
 
diff --git a/README.md b/README.md
index 1ad275816e..98645aeb0d 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ Gateway APIs.
 Built on good intentions and the hope that it will be extendable and reusable, rather than an obstacle for future
 development.
 
-Python 3.8, 3.9, 3.10 and 3.11 are currently supported.
+Python 3.8, 3.9, 3.10, 3.11 and 3.12 are currently supported.
 
 ## Installation
 
diff --git a/changes/1357.feature.md b/changes/1357.feature.md
new file mode 100644
index 0000000000..0593ed2571
--- /dev/null
+++ b/changes/1357.feature.md
@@ -0,0 +1 @@
+Add Python 3.12 support.
diff --git a/hikari/impl/shard.py b/hikari/impl/shard.py
index 7bbe4241a9..48f3b9b4ae 100644
--- a/hikari/impl/shard.py
+++ b/hikari/impl/shard.py
@@ -219,7 +219,8 @@ def _handle_other_message(self, message: aiohttp.WSMessage, /) -> typing.NoRetur
             close_code = int(message.data)
 
             can_reconnect = close_code < 4000 or close_code in _RECONNECTABLE_CLOSE_CODES
-            raise errors.GatewayServerClosedConnectionError(message.extra, close_code, can_reconnect)
+            # str(message.extra) is used to cast the possible None to a string
+            raise errors.GatewayServerClosedConnectionError(str(message.extra), close_code, can_reconnect)
 
         if message.type == aiohttp.WSMsgType.CLOSING or message.type == aiohttp.WSMsgType.CLOSED:
             # May be caused by the server shutting us down.
diff --git a/hikari/internal/fast_protocol.py b/hikari/internal/fast_protocol.py
index a313578039..2e9f3b6f64 100644
--- a/hikari/internal/fast_protocol.py
+++ b/hikari/internal/fast_protocol.py
@@ -32,7 +32,7 @@
     from typing_extensions import Self
 
 _Protocol: FastProtocolChecking = NotImplemented
-_IGNORED_ATTRS = typing.EXCLUDED_ATTRIBUTES + ["__qualname__", "__slots__"]
+_IGNORED_ATTRS = frozenset(typing.EXCLUDED_ATTRIBUTES) | {"__qualname__", "__slots__"}
 
 
 def _check_if_ignored(name: str) -> bool:
diff --git a/requirements.txt b/requirements.txt
index 1526161d40..44ae1bfe00 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-aiohttp~=3.8
+aiohttp~=3.9
 attrs~=23.1
 colorlog~=6.7
 multidict~=6.0
diff --git a/setup.py b/setup.py
index 6ec507f638..e70e11c81a 100644
--- a/setup.py
+++ b/setup.py
@@ -65,7 +65,7 @@ def parse_requirements_file(path):
     maintainer_email=metadata.email,
     license=metadata.license,
     url=metadata.url,
-    python_requires=">=3.8.0,<3.12",
+    python_requires=">=3.8.0,<3.13",
     packages=setuptools.find_namespace_packages(include=["hikari*"]),
     entry_points={"console_scripts": ["hikari = hikari.cli:main"]},
     install_requires=parse_requirements_file("requirements.txt"),
@@ -95,6 +95,7 @@ def parse_requirements_file(path):
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
+        "Programming Language :: Python :: 3.12",
         "Programming Language :: Python :: Implementation :: CPython",
         "Topic :: Communications :: Chat",
         "Topic :: Internet :: WWW/HTTP",
diff --git a/tests/hikari/impl/test_event_manager_base.py b/tests/hikari/impl/test_event_manager_base.py
index ebba1c2ec6..89935f66d2 100644
--- a/tests/hikari/impl/test_event_manager_base.py
+++ b/tests/hikari/impl/test_event_manager_base.py
@@ -572,6 +572,10 @@ async def test_handle_dispatch_ignores_cancelled_errors(self, event_manager, eve
 
     @pytest.mark.asyncio()
     async def test_handle_dispatch_handles_exceptions(self, event_manager, event_loop):
+        mock_task = mock.Mock()
+        # On Python 3.12+ Asyncio uses this to get the task's context if set to call the
+        # error handler in. We want to avoid for this test for simplicity.
+        mock_task.get_context.return_value = None
         event_manager._enabled_for_consumer = mock.Mock(return_value=True)
         exc = Exception("aaaa!")
         consumer = mock.Mock(callback=mock.AsyncMock(side_effect=exc))
@@ -580,12 +584,12 @@ async def test_handle_dispatch_handles_exceptions(self, event_manager, event_loo
         shard = object()
         pl = {"i like": "cats"}
 
-        with mock.patch.object(asyncio, "current_task") as current_task:
+        with mock.patch.object(asyncio, "current_task", return_value=mock_task):
             await event_manager._handle_dispatch(consumer, shard, pl)
 
         error_handler.assert_called_once_with(
             event_loop,
-            {"exception": exc, "message": "Exception occurred in raw event dispatch conduit", "task": current_task()},
+            {"exception": exc, "message": "Exception occurred in raw event dispatch conduit", "task": mock_task},
         )
 
     @pytest.mark.asyncio()