diff --git a/changelog.d/9515.misc b/changelog.d/9515.misc
new file mode 100644
index 0000000000..14c7b78dd9
--- /dev/null
+++ b/changelog.d/9515.misc
@@ -0,0 +1 @@
+Fix incorrect type hints.
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 9ba9f591d9..3978e41518 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -36,7 +36,7 @@ import attr
 import bcrypt
 import pymacaroons
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.constants import LoginType
 from synapse.api.errors import (
@@ -481,7 +481,7 @@ class AuthHandler(BaseHandler):
             sid = authdict["session"]
 
         # Convert the URI and method to strings.
-        uri = request.uri.decode("utf-8")
+        uri = request.uri.decode("utf-8")  # type: ignore
         method = request.method.decode("utf-8")
 
         # If there's no session ID, create a new session.
diff --git a/synapse/handlers/sso.py b/synapse/handlers/sso.py
index 514b1f69d8..80e28bdcbe 100644
--- a/synapse/handlers/sso.py
+++ b/synapse/handlers/sso.py
@@ -31,8 +31,8 @@ from urllib.parse import urlencode
 import attr
 from typing_extensions import NoReturn, Protocol
 
-from twisted.web.http import Request
 from twisted.web.iweb import IRequest
+from twisted.web.server import Request
 
 from synapse.api.constants import LoginType
 from synapse.api.errors import Codes, NotFoundError, RedirectException, SynapseError
diff --git a/synapse/replication/http/membership.py b/synapse/replication/http/membership.py
index 439881be67..c10992ff51 100644
--- a/synapse/replication/http/membership.py
+++ b/synapse/replication/http/membership.py
@@ -15,9 +15,10 @@
 import logging
 from typing import TYPE_CHECKING, List, Optional, Tuple
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.http.servlet import parse_json_object_from_request
+from synapse.http.site import SynapseRequest
 from synapse.replication.http._base import ReplicationEndpoint
 from synapse.types import JsonDict, Requester, UserID
 from synapse.util.distributor import user_left_room
@@ -78,7 +79,7 @@ class ReplicationRemoteJoinRestServlet(ReplicationEndpoint):
         }
 
     async def _handle_request(  # type: ignore
-        self, request: Request, room_id: str, user_id: str
+        self, request: SynapseRequest, room_id: str, user_id: str
     ) -> Tuple[int, JsonDict]:
         content = parse_json_object_from_request(request)
 
@@ -86,7 +87,6 @@ class ReplicationRemoteJoinRestServlet(ReplicationEndpoint):
         event_content = content["content"]
 
         requester = Requester.deserialize(self.store, content["requester"])
-
         request.requester = requester
 
         logger.info("remote_join: %s into room: %s", user_id, room_id)
@@ -147,7 +147,7 @@ class ReplicationRemoteRejectInviteRestServlet(ReplicationEndpoint):
         }
 
     async def _handle_request(  # type: ignore
-        self, request: Request, invite_event_id: str
+        self, request: SynapseRequest, invite_event_id: str
     ) -> Tuple[int, JsonDict]:
         content = parse_json_object_from_request(request)
 
@@ -155,7 +155,6 @@ class ReplicationRemoteRejectInviteRestServlet(ReplicationEndpoint):
         event_content = content["content"]
 
         requester = Requester.deserialize(self.store, content["requester"])
-
         request.requester = requester
 
         # hopefully we're now on the master, so this won't recurse!
diff --git a/synapse/rest/admin/media.py b/synapse/rest/admin/media.py
index b996862c05..511c859f64 100644
--- a/synapse/rest/admin/media.py
+++ b/synapse/rest/admin/media.py
@@ -17,7 +17,7 @@
 import logging
 from typing import TYPE_CHECKING, Tuple
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.errors import AuthError, Codes, NotFoundError, SynapseError
 from synapse.http.servlet import RestServlet, parse_boolean, parse_integer
diff --git a/synapse/rest/client/v2_alpha/groups.py b/synapse/rest/client/v2_alpha/groups.py
index d3434225cb..7aea4cebf5 100644
--- a/synapse/rest/client/v2_alpha/groups.py
+++ b/synapse/rest/client/v2_alpha/groups.py
@@ -18,7 +18,7 @@ import logging
 from functools import wraps
 from typing import TYPE_CHECKING, Optional, Tuple
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.constants import (
     MAX_GROUP_CATEGORYID_LENGTH,
diff --git a/synapse/rest/media/v1/_base.py b/synapse/rest/media/v1/_base.py
index 90bbeca679..6366947071 100644
--- a/synapse/rest/media/v1/_base.py
+++ b/synapse/rest/media/v1/_base.py
@@ -21,7 +21,7 @@ from typing import Awaitable, Dict, Generator, List, Optional, Tuple
 
 from twisted.internet.interfaces import IConsumer
 from twisted.protocols.basic import FileSender
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.errors import Codes, SynapseError, cs_error
 from synapse.http.server import finish_request, respond_with_json
@@ -49,18 +49,20 @@ TEXT_CONTENT_TYPES = [
 
 def parse_media_id(request: Request) -> Tuple[str, str, Optional[str]]:
     try:
+        # The type on postpath seems incorrect in Twisted 21.2.0.
+        postpath = request.postpath  # type: List[bytes]  # type: ignore
+        assert postpath
+
         # This allows users to append e.g. /test.png to the URL. Useful for
         # clients that parse the URL to see content type.
-        server_name, media_id = request.postpath[:2]
-
-        if isinstance(server_name, bytes):
-            server_name = server_name.decode("utf-8")
-            media_id = media_id.decode("utf8")
+        server_name_bytes, media_id_bytes = postpath[:2]
+        server_name = server_name_bytes.decode("utf-8")
+        media_id = media_id_bytes.decode("utf8")
 
         file_name = None
-        if len(request.postpath) > 2:
+        if len(postpath) > 2:
             try:
-                file_name = urllib.parse.unquote(request.postpath[-1].decode("utf-8"))
+                file_name = urllib.parse.unquote(postpath[-1].decode("utf-8"))
             except UnicodeDecodeError:
                 pass
         return server_name, media_id, file_name
diff --git a/synapse/rest/media/v1/config_resource.py b/synapse/rest/media/v1/config_resource.py
index 4e4c6971f7..9039662f7e 100644
--- a/synapse/rest/media/v1/config_resource.py
+++ b/synapse/rest/media/v1/config_resource.py
@@ -17,7 +17,7 @@
 
 from typing import TYPE_CHECKING
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.http.server import DirectServeJsonResource, respond_with_json
 
diff --git a/synapse/rest/media/v1/download_resource.py b/synapse/rest/media/v1/download_resource.py
index 48f4433155..8a43581f1f 100644
--- a/synapse/rest/media/v1/download_resource.py
+++ b/synapse/rest/media/v1/download_resource.py
@@ -16,7 +16,7 @@
 import logging
 from typing import TYPE_CHECKING
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.http.server import DirectServeJsonResource, set_cors_headers
 from synapse.http.servlet import parse_boolean
diff --git a/synapse/rest/media/v1/media_repository.py b/synapse/rest/media/v1/media_repository.py
index 3375455c43..0641924f18 100644
--- a/synapse/rest/media/v1/media_repository.py
+++ b/synapse/rest/media/v1/media_repository.py
@@ -22,8 +22,8 @@ from typing import IO, TYPE_CHECKING, Dict, List, Optional, Set, Tuple
 
 import twisted.internet.error
 import twisted.web.http
-from twisted.web.http import Request
 from twisted.web.resource import Resource
+from twisted.web.server import Request
 
 from synapse.api.errors import (
     FederationDeniedError,
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py
index 89dc6b1c98..a074e807dc 100644
--- a/synapse/rest/media/v1/preview_url_resource.py
+++ b/synapse/rest/media/v1/preview_url_resource.py
@@ -29,7 +29,7 @@ from urllib import parse as urlparse
 import attr
 
 from twisted.internet.error import DNSLookupError
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.errors import Codes, SynapseError
 from synapse.http.client import SimpleHttpClient
diff --git a/synapse/rest/media/v1/thumbnail_resource.py b/synapse/rest/media/v1/thumbnail_resource.py
index 3ab90e9f9b..fbcd50f1e2 100644
--- a/synapse/rest/media/v1/thumbnail_resource.py
+++ b/synapse/rest/media/v1/thumbnail_resource.py
@@ -18,7 +18,7 @@
 import logging
 from typing import TYPE_CHECKING, Any, Dict, List, Optional
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.errors import SynapseError
 from synapse.http.server import DirectServeJsonResource, set_cors_headers
diff --git a/synapse/rest/media/v1/upload_resource.py b/synapse/rest/media/v1/upload_resource.py
index 1136277794..5e104fac40 100644
--- a/synapse/rest/media/v1/upload_resource.py
+++ b/synapse/rest/media/v1/upload_resource.py
@@ -15,9 +15,9 @@
 # limitations under the License.
 
 import logging
-from typing import TYPE_CHECKING
+from typing import IO, TYPE_CHECKING
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.errors import Codes, SynapseError
 from synapse.http.server import DirectServeJsonResource, respond_with_json
@@ -79,7 +79,9 @@ class UploadResource(DirectServeJsonResource):
         headers = request.requestHeaders
 
         if headers.hasHeader(b"Content-Type"):
-            media_type = headers.getRawHeaders(b"Content-Type")[0].decode("ascii")
+            content_type_headers = headers.getRawHeaders(b"Content-Type")
+            assert content_type_headers  # for mypy
+            media_type = content_type_headers[0].decode("ascii")
         else:
             raise SynapseError(msg="Upload request missing 'Content-Type'", code=400)
 
@@ -88,8 +90,9 @@ class UploadResource(DirectServeJsonResource):
         # TODO(markjh): parse content-dispostion
 
         try:
+            content = request.content  # type: IO  # type: ignore
             content_uri = await self.media_repo.create_content(
-                media_type, upload_name, request.content, content_length, requester.user
+                media_type, upload_name, content, content_length, requester.user
             )
         except SpamMediaException:
             # For uploading of media we want to respond with a 400, instead of
diff --git a/synapse/rest/synapse/client/new_user_consent.py b/synapse/rest/synapse/client/new_user_consent.py
index b2e0f93810..78ee0b5e88 100644
--- a/synapse/rest/synapse/client/new_user_consent.py
+++ b/synapse/rest/synapse/client/new_user_consent.py
@@ -15,7 +15,7 @@
 import logging
 from typing import TYPE_CHECKING
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.errors import SynapseError
 from synapse.handlers.sso import get_username_mapping_session_cookie_from_request
diff --git a/synapse/rest/synapse/client/password_reset.py b/synapse/rest/synapse/client/password_reset.py
index 9e4fbc0cbd..d26ce46efc 100644
--- a/synapse/rest/synapse/client/password_reset.py
+++ b/synapse/rest/synapse/client/password_reset.py
@@ -15,7 +15,7 @@
 import logging
 from typing import TYPE_CHECKING, Tuple
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.errors import ThreepidValidationError
 from synapse.config.emailconfig import ThreepidBehaviour
diff --git a/synapse/rest/synapse/client/pick_username.py b/synapse/rest/synapse/client/pick_username.py
index 96077cfcd1..51acaa9a92 100644
--- a/synapse/rest/synapse/client/pick_username.py
+++ b/synapse/rest/synapse/client/pick_username.py
@@ -16,8 +16,8 @@
 import logging
 from typing import TYPE_CHECKING, List
 
-from twisted.web.http import Request
 from twisted.web.resource import Resource
+from twisted.web.server import Request
 
 from synapse.api.errors import SynapseError
 from synapse.handlers.sso import get_username_mapping_session_cookie_from_request
diff --git a/synapse/rest/synapse/client/sso_register.py b/synapse/rest/synapse/client/sso_register.py
index dfefeb7796..f2acce2437 100644
--- a/synapse/rest/synapse/client/sso_register.py
+++ b/synapse/rest/synapse/client/sso_register.py
@@ -16,7 +16,7 @@
 import logging
 from typing import TYPE_CHECKING
 
-from twisted.web.http import Request
+from twisted.web.server import Request
 
 from synapse.api.errors import SynapseError
 from synapse.handlers.sso import get_username_mapping_session_cookie_from_request
diff --git a/tox.ini b/tox.ini
index 9ff70fe312..a6d10537ae 100644
--- a/tox.ini
+++ b/tox.ini
@@ -189,5 +189,7 @@ commands=
 [testenv:mypy]
 deps =
     {[base]deps}
+    # Type hints are broken with Twisted > 20.3.0, see https://github.com/matrix-org/synapse/issues/9513
+    twisted==20.3.0
 extras = all,mypy
 commands = mypy