diff --git a/changelog.d/12402.misc b/changelog.d/12402.misc
new file mode 100644
index 0000000000..51ed8ad44e
--- /dev/null
+++ b/changelog.d/12402.misc
@@ -0,0 +1 @@
+Add missing type hints to configuration classes.
diff --git a/mypy.ini b/mypy.ini
index 4ccea6fa5a..5246f987c0 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -105,7 +105,7 @@ disallow_untyped_defs = True
 [mypy-synapse.appservice.*]
 disallow_untyped_defs = True
 
-[mypy-synapse.config._base]
+[mypy-synapse.config.*]
 disallow_untyped_defs = True
 
 [mypy-synapse.crypto.*]
diff --git a/synapse/_scripts/review_recent_signups.py b/synapse/_scripts/review_recent_signups.py
index e207f154f3..a935c50f42 100644
--- a/synapse/_scripts/review_recent_signups.py
+++ b/synapse/_scripts/review_recent_signups.py
@@ -138,9 +138,7 @@ def main() -> None:
     config_args = parser.parse_args(sys.argv[1:])
     config_files = find_config_files(search_paths=config_args.config_path)
     config_dict = read_config_files(config_files)
-    config.parse_config_dict(
-        config_dict,
-    )
+    config.parse_config_dict(config_dict, "", "")
 
     since_ms = time.time() * 1000 - Config.parse_duration(config_args.since)
     exclude_users_with_email = config_args.exclude_emails
diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index 3e59805baa..37321f9133 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -130,7 +130,7 @@ def start_reactor(
     appname: str,
     soft_file_limit: int,
     gc_thresholds: Optional[Tuple[int, int, int]],
-    pid_file: str,
+    pid_file: Optional[str],
     daemonize: bool,
     print_pidfile: bool,
     logger: logging.Logger,
@@ -171,6 +171,8 @@ def start_reactor(
     # appearing to go backwards.
     with PreserveLoggingContext():
         if daemonize:
+            assert pid_file is not None
+
             if print_pidfile:
                 print(pid_file)
 
diff --git a/synapse/config/_base.py b/synapse/config/_base.py
index 8e19e2fc26..179aa7ff88 100644
--- a/synapse/config/_base.py
+++ b/synapse/config/_base.py
@@ -702,10 +702,7 @@ class RootConfig:
         return obj
 
     def parse_config_dict(
-        self,
-        config_dict: Dict[str, Any],
-        config_dir_path: Optional[str] = None,
-        data_dir_path: Optional[str] = None,
+        self, config_dict: Dict[str, Any], config_dir_path: str, data_dir_path: str
     ) -> None:
         """Read the information from the config dict into this Config object.
 
diff --git a/synapse/config/_base.pyi b/synapse/config/_base.pyi
index 363d8b4554..bd092f956d 100644
--- a/synapse/config/_base.pyi
+++ b/synapse/config/_base.pyi
@@ -124,10 +124,7 @@ class RootConfig:
     @classmethod
     def invoke_all_static(cls, func_name: str, *args: Any, **kwargs: Any) -> None: ...
     def parse_config_dict(
-        self,
-        config_dict: Dict[str, Any],
-        config_dir_path: Optional[str] = ...,
-        data_dir_path: Optional[str] = ...,
+        self, config_dict: Dict[str, Any], config_dir_path: str, data_dir_path: str
     ) -> None: ...
     def generate_config(
         self,
diff --git a/synapse/config/account_validity.py b/synapse/config/account_validity.py
index c533452cab..d1335e77cd 100644
--- a/synapse/config/account_validity.py
+++ b/synapse/config/account_validity.py
@@ -12,8 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
+from typing import Any
 
 from synapse.config._base import Config, ConfigError
+from synapse.types import JsonDict
 
 logger = logging.getLogger(__name__)
 
@@ -29,7 +31,7 @@ https://matrix-org.github.io/synapse/latest/templates.html
 class AccountValidityConfig(Config):
     section = "account_validity"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         """Parses the old account validity config. The config format looks like this:
 
         account_validity:
diff --git a/synapse/config/api.py b/synapse/config/api.py
index 8133b6b624..2cc6305340 100644
--- a/synapse/config/api.py
+++ b/synapse/config/api.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 import logging
-from typing import Iterable
+from typing import Any, Iterable
 
 from synapse.api.constants import EventTypes
 from synapse.config._base import Config, ConfigError
@@ -26,12 +26,12 @@ logger = logging.getLogger(__name__)
 class ApiConfig(Config):
     section = "api"
 
-    def read_config(self, config: JsonDict, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         validate_config(_MAIN_SCHEMA, config, ())
         self.room_prejoin_state = list(self._get_prejoin_state_types(config))
         self.track_puppeted_user_ips = config.get("track_puppeted_user_ips", False)
 
-    def generate_config_section(cls, **kwargs) -> str:
+    def generate_config_section(cls, **kwargs: Any) -> str:
         formatted_default_state_types = "\n".join(
             "           # - %s" % (t,) for t in _DEFAULT_PREJOIN_STATE_TYPES
         )
diff --git a/synapse/config/appservice.py b/synapse/config/appservice.py
index ada165f238..720b90a283 100644
--- a/synapse/config/appservice.py
+++ b/synapse/config/appservice.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 
 import logging
-from typing import Dict, List
+from typing import Any, Dict, List
 from urllib import parse as urlparse
 
 import yaml
@@ -31,12 +31,12 @@ logger = logging.getLogger(__name__)
 class AppServiceConfig(Config):
     section = "appservice"
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.app_service_config_files = config.get("app_service_config_files", [])
         self.notify_appservices = config.get("notify_appservices", True)
         self.track_appservice_user_ips = config.get("track_appservice_user_ips", False)
 
-    def generate_config_section(cls, **kwargs) -> str:
+    def generate_config_section(cls, **kwargs: Any) -> str:
         return """\
         # A list of application service config files to use
         #
diff --git a/synapse/config/auth.py b/synapse/config/auth.py
index ba8bf9cbe7..bb417a2359 100644
--- a/synapse/config/auth.py
+++ b/synapse/config/auth.py
@@ -12,6 +12,9 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from typing import Any
+
+from synapse.types import JsonDict
 
 from ._base import Config
 
@@ -21,7 +24,7 @@ class AuthConfig(Config):
 
     section = "auth"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         password_config = config.get("password_config", {})
         if password_config is None:
             password_config = {}
@@ -40,7 +43,7 @@ class AuthConfig(Config):
             ui_auth.get("session_timeout", 0)
         )
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         password_config:
            # Uncomment to disable password login
diff --git a/synapse/config/background_updates.py b/synapse/config/background_updates.py
index f6cdeacc4b..07fadbe041 100644
--- a/synapse/config/background_updates.py
+++ b/synapse/config/background_updates.py
@@ -11,6 +11,9 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from typing import Any
+
+from synapse.types import JsonDict
 
 from ._base import Config
 
@@ -18,7 +21,7 @@ from ._base import Config
 class BackgroundUpdateConfig(Config):
     section = "background_updates"
 
-    def generate_config_section(self, **kwargs) -> str:
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         ## Background Updates ##
 
@@ -52,7 +55,7 @@ class BackgroundUpdateConfig(Config):
             #default_batch_size: 50
         """
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         bg_update_config = config.get("background_updates") or {}
 
         self.update_duration_ms = bg_update_config.get(
diff --git a/synapse/config/cache.py b/synapse/config/cache.py
index 9a68da9c33..94d852f413 100644
--- a/synapse/config/cache.py
+++ b/synapse/config/cache.py
@@ -16,10 +16,11 @@ import logging
 import os
 import re
 import threading
-from typing import Callable, Dict, Optional
+from typing import Any, Callable, Dict, Optional
 
 import attr
 
+from synapse.types import JsonDict
 from synapse.util.check_dependencies import DependencyException, check_requirements
 
 from ._base import Config, ConfigError
@@ -105,7 +106,7 @@ class CacheConfig(Config):
         with _CACHES_LOCK:
             _CACHES.clear()
 
-    def generate_config_section(self, **kwargs) -> str:
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         ## Caching ##
 
@@ -172,7 +173,7 @@ class CacheConfig(Config):
           #sync_response_cache_duration: 2m
         """
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.event_cache_size = self.parse_size(
             config.get("event_cache_size", _DEFAULT_EVENT_CACHE_SIZE)
         )
diff --git a/synapse/config/captcha.py b/synapse/config/captcha.py
index 9e48f865cc..92c603f224 100644
--- a/synapse/config/captcha.py
+++ b/synapse/config/captcha.py
@@ -12,15 +12,31 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from ._base import Config
+from typing import Any
+
+from synapse.types import JsonDict
+
+from ._base import Config, ConfigError
 
 
 class CaptchaConfig(Config):
     section = "captcha"
 
-    def read_config(self, config, **kwargs):
-        self.recaptcha_private_key = config.get("recaptcha_private_key")
-        self.recaptcha_public_key = config.get("recaptcha_public_key")
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
+        recaptcha_private_key = config.get("recaptcha_private_key")
+        if recaptcha_private_key is not None and not isinstance(
+            recaptcha_private_key, str
+        ):
+            raise ConfigError("recaptcha_private_key must be a string.")
+        self.recaptcha_private_key = recaptcha_private_key
+
+        recaptcha_public_key = config.get("recaptcha_public_key")
+        if recaptcha_public_key is not None and not isinstance(
+            recaptcha_public_key, str
+        ):
+            raise ConfigError("recaptcha_public_key must be a string.")
+        self.recaptcha_public_key = recaptcha_public_key
+
         self.enable_registration_captcha = config.get(
             "enable_registration_captcha", False
         )
@@ -30,7 +46,7 @@ class CaptchaConfig(Config):
         )
         self.recaptcha_template = self.read_template("recaptcha.html")
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         ## Captcha ##
         # See docs/CAPTCHA_SETUP.md for full details of configuring this.
diff --git a/synapse/config/cas.py b/synapse/config/cas.py
index 6f2754092e..8af0794ba4 100644
--- a/synapse/config/cas.py
+++ b/synapse/config/cas.py
@@ -16,6 +16,7 @@
 from typing import Any, List
 
 from synapse.config.sso import SsoAttributeRequirement
+from synapse.types import JsonDict
 
 from ._base import Config
 from ._util import validate_config
@@ -29,7 +30,7 @@ class CasConfig(Config):
 
     section = "cas"
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         cas_config = config.get("cas_config", None)
         self.cas_enabled = cas_config and cas_config.get("enabled", True)
 
@@ -52,7 +53,7 @@ class CasConfig(Config):
             self.cas_displayname_attribute = None
             self.cas_required_attributes = []
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs) -> str:
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         # Enable Central Authentication Service (CAS) for registration and login.
         #
diff --git a/synapse/config/consent.py b/synapse/config/consent.py
index ecc43b08b9..8ee3d34521 100644
--- a/synapse/config/consent.py
+++ b/synapse/config/consent.py
@@ -13,9 +13,10 @@
 # limitations under the License.
 
 from os import path
-from typing import Optional
+from typing import Any, Optional
 
 from synapse.config import ConfigError
+from synapse.types import JsonDict
 
 from ._base import Config
 
@@ -76,18 +77,18 @@ class ConsentConfig(Config):
 
     section = "consent"
 
-    def __init__(self, *args):
+    def __init__(self, *args: Any):
         super().__init__(*args)
 
         self.user_consent_version: Optional[str] = None
         self.user_consent_template_dir: Optional[str] = None
-        self.user_consent_server_notice_content = None
+        self.user_consent_server_notice_content: Optional[JsonDict] = None
         self.user_consent_server_notice_to_guests = False
-        self.block_events_without_consent_error = None
+        self.block_events_without_consent_error: Optional[str] = None
         self.user_consent_at_registration = False
         self.user_consent_policy_name = "Privacy Policy"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         consent_config = config.get("user_consent")
         self.terms_template = self.read_template("terms.html")
 
@@ -118,5 +119,5 @@ class ConsentConfig(Config):
             "policy_name", "Privacy Policy"
         )
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return DEFAULT_CONFIG
diff --git a/synapse/config/database.py b/synapse/config/database.py
index d7f2219f53..de0d3ca0f0 100644
--- a/synapse/config/database.py
+++ b/synapse/config/database.py
@@ -15,8 +15,10 @@
 import argparse
 import logging
 import os
+from typing import Any, List
 
 from synapse.config._base import Config, ConfigError
+from synapse.types import JsonDict
 
 logger = logging.getLogger(__name__)
 
@@ -121,12 +123,12 @@ class DatabaseConnectionConfig:
 class DatabaseConfig(Config):
     section = "database"
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
+    def __init__(self, *args: Any):
+        super().__init__(*args)
 
-        self.databases = []
+        self.databases: List[DatabaseConnectionConfig] = []
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         # We *experimentally* support specifying multiple databases via the
         # `databases` key. This is a map from a label to database config in the
         # same format as the `database` config option, plus an extra
@@ -170,7 +172,7 @@ class DatabaseConfig(Config):
             self.databases = [DatabaseConnectionConfig("master", database_config)]
             self.set_databasepath(database_path)
 
-    def generate_config_section(self, data_dir_path, **kwargs) -> str:
+    def generate_config_section(self, data_dir_path: str, **kwargs: Any) -> str:
         return DEFAULT_CONFIG % {
             "database_path": os.path.join(data_dir_path, "homeserver.db")
         }
diff --git a/synapse/config/emailconfig.py b/synapse/config/emailconfig.py
index 949d7dd5ac..5b5c2f4fff 100644
--- a/synapse/config/emailconfig.py
+++ b/synapse/config/emailconfig.py
@@ -19,9 +19,12 @@ import email.utils
 import logging
 import os
 from enum import Enum
+from typing import Any
 
 import attr
 
+from synapse.types import JsonDict
+
 from ._base import Config, ConfigError
 
 logger = logging.getLogger(__name__)
@@ -73,7 +76,7 @@ class EmailSubjectConfig:
 class EmailConfig(Config):
     section = "email"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         # TODO: We should separate better the email configuration from the notification
         # and account validity config.
 
@@ -354,7 +357,7 @@ class EmailConfig(Config):
                     path=("email", "invite_client_location"),
                 )
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return (
             """\
         # Configuration for sending emails from Synapse.
diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py
index 43db5fcdd9..0dd4c59581 100644
--- a/synapse/config/experimental.py
+++ b/synapse/config/experimental.py
@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any
+
 from synapse.config._base import Config
 from synapse.types import JsonDict
 
@@ -21,7 +23,7 @@ class ExperimentalConfig(Config):
 
     section = "experimental"
 
-    def read_config(self, config: JsonDict, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         experimental = config.get("experimental_features") or {}
 
         # MSC3440 (thread relation)
diff --git a/synapse/config/federation.py b/synapse/config/federation.py
index 7d64993e22..0e74f70784 100644
--- a/synapse/config/federation.py
+++ b/synapse/config/federation.py
@@ -11,16 +11,17 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from typing import Optional
+from typing import Any, Optional
 
 from synapse.config._base import Config
 from synapse.config._util import validate_config
+from synapse.types import JsonDict
 
 
 class FederationConfig(Config):
     section = "federation"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         # FIXME: federation_domain_whitelist needs sytests
         self.federation_domain_whitelist: Optional[dict] = None
         federation_domain_whitelist = config.get("federation_domain_whitelist", None)
@@ -48,7 +49,7 @@ class FederationConfig(Config):
             "allow_device_name_lookup_over_federation", True
         )
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         ## Federation ##
 
diff --git a/synapse/config/groups.py b/synapse/config/groups.py
index 15c2e64bda..c9b9c6daad 100644
--- a/synapse/config/groups.py
+++ b/synapse/config/groups.py
@@ -12,17 +12,21 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any
+
+from synapse.types import JsonDict
+
 from ._base import Config
 
 
 class GroupsConfig(Config):
     section = "groups"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.enable_group_creation = config.get("enable_group_creation", False)
         self.group_creation_prefix = config.get("group_creation_prefix", "")
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         # Uncomment to allow non-server-admin users to create groups on this server
         #
diff --git a/synapse/config/jwt.py b/synapse/config/jwt.py
index 24c3ef01fc..2a756d1a7c 100644
--- a/synapse/config/jwt.py
+++ b/synapse/config/jwt.py
@@ -12,6 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any
+
+from synapse.types import JsonDict
+
 from ._base import Config, ConfigError
 
 MISSING_JWT = """Missing jwt library. This is required for jwt login.
@@ -24,7 +28,7 @@ MISSING_JWT = """Missing jwt library. This is required for jwt login.
 class JWTConfig(Config):
     section = "jwt"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         jwt_config = config.get("jwt_config", None)
         if jwt_config:
             self.jwt_enabled = jwt_config.get("enabled", False)
@@ -52,7 +56,7 @@ class JWTConfig(Config):
             self.jwt_issuer = None
             self.jwt_audiences = None
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         # JSON web token integration. The following settings can be used to make
         # Synapse JSON web tokens for authentication, instead of its internal
diff --git a/synapse/config/key.py b/synapse/config/key.py
index f5377e7d9c..ada65f6dd6 100644
--- a/synapse/config/key.py
+++ b/synapse/config/key.py
@@ -99,11 +99,14 @@ class TrustedKeyServer:
 class KeyConfig(Config):
     section = "key"
 
-    def read_config(self, config, config_dir_path, **kwargs):
+    def read_config(
+        self, config: JsonDict, config_dir_path: str, **kwargs: Any
+    ) -> None:
         # the signing key can be specified inline or in a separate file
         if "signing_key" in config:
             self.signing_key = read_signing_keys([config["signing_key"]])
         else:
+            assert config_dir_path is not None
             signing_key_path = config.get("signing_key_path")
             if signing_key_path is None:
                 signing_key_path = os.path.join(
@@ -172,8 +175,12 @@ class KeyConfig(Config):
         self.form_secret = config.get("form_secret", None)
 
     def generate_config_section(
-        self, config_dir_path, server_name, generate_secrets=False, **kwargs
-    ):
+        self,
+        config_dir_path: str,
+        server_name: str,
+        generate_secrets: bool = False,
+        **kwargs: Any,
+    ) -> str:
         base_key_name = os.path.join(config_dir_path, server_name)
 
         if generate_secrets:
diff --git a/synapse/config/logger.py b/synapse/config/logger.py
index cbbe221965..99db9e1e39 100644
--- a/synapse/config/logger.py
+++ b/synapse/config/logger.py
@@ -35,6 +35,7 @@ from twisted.logger import (
 
 from synapse.logging.context import LoggingContextFilter
 from synapse.logging.filter import MetadataFilter
+from synapse.types import JsonDict
 
 from ._base import Config, ConfigError
 
@@ -147,13 +148,15 @@ https://matrix-org.github.io/synapse/v1.54/structured_logging.html
 class LoggingConfig(Config):
     section = "logging"
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         if config.get("log_file"):
             raise ConfigError(LOG_FILE_ERROR)
         self.log_config = self.abspath(config.get("log_config"))
         self.no_redirect_stdio = config.get("no_redirect_stdio", False)
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs) -> str:
+    def generate_config_section(
+        self, config_dir_path: str, server_name: str, **kwargs: Any
+    ) -> str:
         log_config = os.path.join(config_dir_path, server_name + ".log.config")
         return (
             """\
diff --git a/synapse/config/metrics.py b/synapse/config/metrics.py
index f62292ecf6..aa360a417c 100644
--- a/synapse/config/metrics.py
+++ b/synapse/config/metrics.py
@@ -13,8 +13,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any, Optional
+
 import attr
 
+from synapse.types import JsonDict
 from synapse.util.check_dependencies import DependencyException, check_requirements
 
 from ._base import Config, ConfigError
@@ -37,7 +40,7 @@ class MetricsFlags:
 class MetricsConfig(Config):
     section = "metrics"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.enable_metrics = config.get("enable_metrics", False)
         self.report_stats = config.get("report_stats", None)
         self.report_stats_endpoint = config.get(
@@ -67,7 +70,9 @@ class MetricsConfig(Config):
                     "sentry.dsn field is required when sentry integration is enabled"
                 )
 
-    def generate_config_section(self, report_stats=None, **kwargs):
+    def generate_config_section(
+        self, report_stats: Optional[bool] = None, **kwargs: Any
+    ) -> str:
         res = """\
         ## Metrics ###
 
diff --git a/synapse/config/modules.py b/synapse/config/modules.py
index 2ef02b8f55..0915014f7d 100644
--- a/synapse/config/modules.py
+++ b/synapse/config/modules.py
@@ -14,13 +14,14 @@
 from typing import Any, Dict, List, Tuple
 
 from synapse.config._base import Config, ConfigError
+from synapse.types import JsonDict
 from synapse.util.module_loader import load_module
 
 
 class ModulesConfig(Config):
     section = "modules"
 
-    def read_config(self, config: dict, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.loaded_modules: List[Tuple[Any, Dict]] = []
 
         configured_modules = config.get("modules") or []
@@ -31,7 +32,7 @@ class ModulesConfig(Config):
 
             self.loaded_modules.append(load_module(module, config_path))
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """
             ## Modules ##
 
diff --git a/synapse/config/oembed.py b/synapse/config/oembed.py
index ea6ace4729..690ffb5296 100644
--- a/synapse/config/oembed.py
+++ b/synapse/config/oembed.py
@@ -40,7 +40,7 @@ class OembedConfig(Config):
 
     section = "oembed"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         oembed_config: Dict[str, Any] = config.get("oembed") or {}
 
         # A list of patterns which will be used.
@@ -143,7 +143,7 @@ class OembedConfig(Config):
         )
         return re.compile(pattern)
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         # oEmbed allows for easier embedding content from a website. It can be
         # used for generating URLs previews of services which support it.
diff --git a/synapse/config/oidc.py b/synapse/config/oidc.py
index 5d571651cb..b9c40522d8 100644
--- a/synapse/config/oidc.py
+++ b/synapse/config/oidc.py
@@ -36,7 +36,7 @@ LEGACY_USER_MAPPING_PROVIDER = "synapse.handlers.oidc_handler.JinjaOidcMappingPr
 class OIDCConfig(Config):
     section = "oidc"
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.oidc_providers = tuple(_parse_oidc_provider_configs(config))
         if not self.oidc_providers:
             return
@@ -66,7 +66,7 @@ class OIDCConfig(Config):
         # OIDC is enabled if we have a provider
         return bool(self.oidc_providers)
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs) -> str:
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         # List of OpenID Connect (OIDC) / OAuth 2.0 identity providers, for registration
         # and login.
diff --git a/synapse/config/password_auth_providers.py b/synapse/config/password_auth_providers.py
index f980102b45..35df425425 100644
--- a/synapse/config/password_auth_providers.py
+++ b/synapse/config/password_auth_providers.py
@@ -14,6 +14,7 @@
 
 from typing import Any, List, Tuple, Type
 
+from synapse.types import JsonDict
 from synapse.util.module_loader import load_module
 
 from ._base import Config
@@ -24,7 +25,7 @@ LDAP_PROVIDER = "ldap_auth_provider.LdapAuthProvider"
 class PasswordAuthProviderConfig(Config):
     section = "authproviders"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         """Parses the old password auth providers config. The config format looks like this:
 
         password_providers:
diff --git a/synapse/config/push.py b/synapse/config/push.py
index 6ef8491caf..2e796d1c46 100644
--- a/synapse/config/push.py
+++ b/synapse/config/push.py
@@ -13,13 +13,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any
+
+from synapse.types import JsonDict
+
 from ._base import Config
 
 
 class PushConfig(Config):
     section = "push"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         push_config = config.get("push") or {}
         self.push_include_content = push_config.get("include_content", True)
         self.push_group_unread_count_by_room = push_config.get(
@@ -46,7 +50,7 @@ class PushConfig(Config):
             )
             self.push_include_content = not redact_content
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """
         ## Push ##
 
diff --git a/synapse/config/ratelimiting.py b/synapse/config/ratelimiting.py
index e9ccf1bd62..0587f5c10f 100644
--- a/synapse/config/ratelimiting.py
+++ b/synapse/config/ratelimiting.py
@@ -12,10 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Dict, Optional
+from typing import Any, Dict, Optional
 
 import attr
 
+from synapse.types import JsonDict
+
 from ._base import Config
 
 
@@ -43,7 +45,7 @@ class FederationRateLimitConfig:
 class RatelimitConfig(Config):
     section = "ratelimiting"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
 
         # Load the new-style messages config if it exists. Otherwise fall back
         # to the old method.
@@ -142,7 +144,7 @@ class RatelimitConfig(Config):
             },
         )
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         ## Ratelimiting ##
 
diff --git a/synapse/config/redis.py b/synapse/config/redis.py
index bdb1aac3a2..ec7a735418 100644
--- a/synapse/config/redis.py
+++ b/synapse/config/redis.py
@@ -12,14 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any
+
 from synapse.config._base import Config
+from synapse.types import JsonDict
 from synapse.util.check_dependencies import check_requirements
 
 
 class RedisConfig(Config):
     section = "redis"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         redis_config = config.get("redis") or {}
         self.redis_enabled = redis_config.get("enabled", False)
 
@@ -32,7 +35,7 @@ class RedisConfig(Config):
         self.redis_port = redis_config.get("port", 6379)
         self.redis_password = redis_config.get("password")
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         # Configuration for Redis when using workers. This *must* be enabled when
         # using workers (unless using old style direct TCP configuration).
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index 40fb329a7f..39e9acb62a 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -13,18 +13,18 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import argparse
-from typing import Optional
+from typing import Any, Optional
 
 from synapse.api.constants import RoomCreationPreset
 from synapse.config._base import Config, ConfigError
-from synapse.types import RoomAlias, UserID
+from synapse.types import JsonDict, RoomAlias, UserID
 from synapse.util.stringutils import random_string_with_symbols, strtobool
 
 
 class RegistrationConfig(Config):
     section = "registration"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.enable_registration = strtobool(
             str(config.get("enable_registration", False))
         )
@@ -196,7 +196,9 @@ class RegistrationConfig(Config):
 
         self.inhibit_user_in_use_error = config.get("inhibit_user_in_use_error", False)
 
-    def generate_config_section(self, generate_secrets=False, **kwargs):
+    def generate_config_section(
+        self, generate_secrets: bool = False, **kwargs: Any
+    ) -> str:
         if generate_secrets:
             registration_shared_secret = 'registration_shared_secret: "%s"' % (
                 random_string_with_symbols(50),
diff --git a/synapse/config/repository.py b/synapse/config/repository.py
index 0a0d901bfb..98d8a16621 100644
--- a/synapse/config/repository.py
+++ b/synapse/config/repository.py
@@ -14,7 +14,7 @@
 
 import logging
 import os
-from typing import Dict, List, Tuple
+from typing import Any, Dict, List, Tuple
 from urllib.request import getproxies_environment  # type: ignore
 
 import attr
@@ -94,7 +94,7 @@ def parse_thumbnail_requirements(
 class ContentRepositoryConfig(Config):
     section = "media"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
 
         # Only enable the media repo if either the media repo is enabled or the
         # current worker app is the media repo.
@@ -223,7 +223,8 @@ class ContentRepositoryConfig(Config):
                 "url_preview_accept_language"
             ) or ["en"]
 
-    def generate_config_section(self, data_dir_path, **kwargs):
+    def generate_config_section(self, data_dir_path: str, **kwargs: Any) -> str:
+        assert data_dir_path is not None
         media_store = os.path.join(data_dir_path, "media_store")
 
         formatted_thumbnail_sizes = "".join(
diff --git a/synapse/config/retention.py b/synapse/config/retention.py
index aed9bf458f..03b723b84b 100644
--- a/synapse/config/retention.py
+++ b/synapse/config/retention.py
@@ -13,11 +13,12 @@
 #  limitations under the License.
 
 import logging
-from typing import List, Optional
+from typing import Any, List, Optional
 
 import attr
 
 from synapse.config._base import Config, ConfigError
+from synapse.types import JsonDict
 
 logger = logging.getLogger(__name__)
 
@@ -34,7 +35,7 @@ class RetentionPurgeJob:
 class RetentionConfig(Config):
     section = "retention"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         retention_config = config.get("retention")
         if retention_config is None:
             retention_config = {}
@@ -153,7 +154,7 @@ class RetentionConfig(Config):
                 RetentionPurgeJob(self.parse_duration("1d"), None, None)
             ]
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         # Message retention policy at the server level.
         #
diff --git a/synapse/config/room.py b/synapse/config/room.py
index d889d90dbc..e18a87ea37 100644
--- a/synapse/config/room.py
+++ b/synapse/config/room.py
@@ -13,8 +13,10 @@
 # limitations under the License.
 
 import logging
+from typing import Any
 
 from synapse.api.constants import RoomCreationPreset
+from synapse.types import JsonDict
 
 from ._base import Config, ConfigError
 
@@ -32,7 +34,7 @@ class RoomDefaultEncryptionTypes:
 class RoomConfig(Config):
     section = "room"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         # Whether new, locally-created rooms should have encryption enabled
         encryption_for_room_type = config.get(
             "encryption_enabled_by_default_for_room_type",
@@ -61,7 +63,7 @@ class RoomConfig(Config):
                 "Invalid value for encryption_enabled_by_default_for_room_type"
             )
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         ## Rooms ##
 
diff --git a/synapse/config/room_directory.py b/synapse/config/room_directory.py
index 3c5e0f7ce7..717ba70e1c 100644
--- a/synapse/config/room_directory.py
+++ b/synapse/config/room_directory.py
@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import List
+from typing import Any, List
 
 from matrix_common.regex import glob_to_regex
 
@@ -25,7 +25,7 @@ from ._base import Config, ConfigError
 class RoomDirectoryConfig(Config):
     section = "roomdirectory"
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.enable_room_list_search = config.get("enable_room_list_search", True)
 
         alias_creation_rules = config.get("alias_creation_rules")
@@ -52,7 +52,7 @@ class RoomDirectoryConfig(Config):
                 _RoomDirectoryRule("room_list_publication_rules", {"action": "allow"})
             ]
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs) -> str:
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """
         # Uncomment to disable searching the public room list. When disabled
         # blocks searching local and remote room lists for local and remote
diff --git a/synapse/config/saml2.py b/synapse/config/saml2.py
index 43c456d5c6..19b2f1b215 100644
--- a/synapse/config/saml2.py
+++ b/synapse/config/saml2.py
@@ -65,7 +65,7 @@ def _dict_merge(merge_dict: dict, into_dict: dict) -> None:
 class SAML2Config(Config):
     section = "saml2"
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.saml2_enabled = False
 
         saml2_config = config.get("saml2_config")
@@ -165,13 +165,13 @@ class SAML2Config(Config):
         config_path = saml2_config.get("config_path", None)
         if config_path is not None:
             mod = load_python_module(config_path)
-            config = getattr(mod, "CONFIG", None)
-            if config is None:
+            config_dict_from_file = getattr(mod, "CONFIG", None)
+            if config_dict_from_file is None:
                 raise ConfigError(
                     "Config path specified by saml2_config.config_path does not "
                     "have a CONFIG property."
                 )
-            _dict_merge(merge_dict=config, into_dict=saml2_config_dict)
+            _dict_merge(merge_dict=config_dict_from_file, into_dict=saml2_config_dict)
 
         import saml2.config
 
@@ -223,7 +223,7 @@ class SAML2Config(Config):
             },
         }
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs) -> str:
+    def generate_config_section(self, config_dir_path: str, **kwargs: Any) -> str:
         return """\
         ## Single sign-on integration ##
 
diff --git a/synapse/config/server.py b/synapse/config/server.py
index b3a9e50752..415279d269 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -248,7 +248,7 @@ class LimitRemoteRoomsConfig:
 class ServerConfig(Config):
     section = "server"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.server_name = config["server_name"]
         self.server_context = config.get("server_context", None)
 
@@ -259,8 +259,8 @@ class ServerConfig(Config):
 
         self.pid_file = self.abspath(config.get("pid_file"))
         self.soft_file_limit = config.get("soft_file_limit", 0)
-        self.daemonize = config.get("daemonize")
-        self.print_pidfile = config.get("print_pidfile")
+        self.daemonize = bool(config.get("daemonize"))
+        self.print_pidfile = bool(config.get("print_pidfile"))
         self.user_agent_suffix = config.get("user_agent_suffix")
         self.use_frozen_dicts = config.get("use_frozen_dicts", False)
         self.serve_server_wellknown = config.get("serve_server_wellknown", False)
@@ -697,13 +697,13 @@ class ServerConfig(Config):
 
     def generate_config_section(
         self,
-        server_name,
-        data_dir_path,
-        open_private_ports,
-        listeners,
-        config_dir_path,
-        **kwargs,
-    ):
+        config_dir_path: str,
+        data_dir_path: str,
+        server_name: str,
+        open_private_ports: bool,
+        listeners: Optional[List[dict]],
+        **kwargs: Any,
+    ) -> str:
         ip_range_blacklist = "\n".join(
             "        #  - '%s'" % ip for ip in DEFAULT_IP_RANGE_BLACKLIST
         )
diff --git a/synapse/config/server_notices.py b/synapse/config/server_notices.py
index bde4e879d9..505b4f6c6c 100644
--- a/synapse/config/server_notices.py
+++ b/synapse/config/server_notices.py
@@ -11,7 +11,10 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from synapse.types import UserID
+
+from typing import Any, Optional
+
+from synapse.types import JsonDict, UserID
 
 from ._base import Config
 
@@ -60,14 +63,14 @@ class ServerNoticesConfig(Config):
 
     section = "servernotices"
 
-    def __init__(self, *args):
+    def __init__(self, *args: Any):
         super().__init__(*args)
-        self.server_notices_mxid = None
-        self.server_notices_mxid_display_name = None
-        self.server_notices_mxid_avatar_url = None
-        self.server_notices_room_name = None
+        self.server_notices_mxid: Optional[str] = None
+        self.server_notices_mxid_display_name: Optional[str] = None
+        self.server_notices_mxid_avatar_url: Optional[str] = None
+        self.server_notices_room_name: Optional[str] = None
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         c = config.get("server_notices")
         if c is None:
             return
@@ -81,5 +84,5 @@ class ServerNoticesConfig(Config):
         # todo: i18n
         self.server_notices_room_name = c.get("room_name", "Server Notices")
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return DEFAULT_CONFIG
diff --git a/synapse/config/spam_checker.py b/synapse/config/spam_checker.py
index 4c52103b1c..f22784f9c9 100644
--- a/synapse/config/spam_checker.py
+++ b/synapse/config/spam_checker.py
@@ -16,6 +16,7 @@ import logging
 from typing import Any, Dict, List, Tuple
 
 from synapse.config import ConfigError
+from synapse.types import JsonDict
 from synapse.util.module_loader import load_module
 
 from ._base import Config
@@ -33,7 +34,7 @@ see https://matrix-org.github.io/synapse/latest/modules/index.html
 class SpamCheckerConfig(Config):
     section = "spamchecker"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.spam_checkers: List[Tuple[Any, Dict]] = []
 
         spam_checkers = config.get("spam_checker") or []
diff --git a/synapse/config/sso.py b/synapse/config/sso.py
index e4a4243261..f88eba77d0 100644
--- a/synapse/config/sso.py
+++ b/synapse/config/sso.py
@@ -16,6 +16,8 @@ from typing import Any, Dict, Optional
 
 import attr
 
+from synapse.types import JsonDict
+
 from ._base import Config
 
 logger = logging.getLogger(__name__)
@@ -49,7 +51,7 @@ class SSOConfig(Config):
 
     section = "sso"
 
-    def read_config(self, config, **kwargs) -> None:
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         sso_config: Dict[str, Any] = config.get("sso") or {}
 
         # The sso-specific template_dir
@@ -106,7 +108,7 @@ class SSOConfig(Config):
         )
         self.sso_client_whitelist.append(login_fallback_url)
 
-    def generate_config_section(self, **kwargs) -> str:
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         # Additional settings to use with single-sign on systems such as OpenID Connect,
         # SAML2 and CAS.
diff --git a/synapse/config/stats.py b/synapse/config/stats.py
index 6f253e00c0..ed1f416e4f 100644
--- a/synapse/config/stats.py
+++ b/synapse/config/stats.py
@@ -13,6 +13,9 @@
 # limitations under the License.
 
 import logging
+from typing import Any
+
+from synapse.types import JsonDict
 
 from ._base import Config
 
@@ -36,7 +39,7 @@ class StatsConfig(Config):
 
     section = "stats"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.stats_enabled = True
         stats_config = config.get("stats", None)
         if stats_config:
@@ -44,7 +47,7 @@ class StatsConfig(Config):
         if not self.stats_enabled:
             logger.warning(ROOM_STATS_DISABLED_WARN)
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """
         # Settings for local room and user statistics collection. See
         # https://matrix-org.github.io/synapse/latest/room_and_user_statistics.html.
diff --git a/synapse/config/third_party_event_rules.py b/synapse/config/third_party_event_rules.py
index a3fae02420..eca209d52f 100644
--- a/synapse/config/third_party_event_rules.py
+++ b/synapse/config/third_party_event_rules.py
@@ -12,6 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any
+
+from synapse.types import JsonDict
 from synapse.util.module_loader import load_module
 
 from ._base import Config
@@ -20,7 +23,7 @@ from ._base import Config
 class ThirdPartyRulesConfig(Config):
     section = "thirdpartyrules"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.third_party_event_rules = None
 
         provider = config.get("third_party_event_rules", None)
diff --git a/synapse/config/tls.py b/synapse/config/tls.py
index 6e673d65a7..cb17950d25 100644
--- a/synapse/config/tls.py
+++ b/synapse/config/tls.py
@@ -14,7 +14,7 @@
 
 import logging
 import os
-from typing import List, Optional, Pattern
+from typing import Any, List, Optional, Pattern
 
 from matrix_common.regex import glob_to_regex
 
@@ -22,6 +22,7 @@ from OpenSSL import SSL, crypto
 from twisted.internet._sslverify import Certificate, trustRootFromCertificates
 
 from synapse.config._base import Config, ConfigError
+from synapse.types import JsonDict
 
 logger = logging.getLogger(__name__)
 
@@ -29,7 +30,7 @@ logger = logging.getLogger(__name__)
 class TlsConfig(Config):
     section = "tls"
 
-    def read_config(self, config: dict, config_dir_path: str, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
 
         self.tls_certificate_file = self.abspath(config.get("tls_certificate_path"))
         self.tls_private_key_file = self.abspath(config.get("tls_private_key_path"))
@@ -142,13 +143,13 @@ class TlsConfig(Config):
 
     def generate_config_section(
         self,
-        config_dir_path,
-        server_name,
-        data_dir_path,
-        tls_certificate_path,
-        tls_private_key_path,
-        **kwargs,
-    ):
+        config_dir_path: str,
+        data_dir_path: str,
+        server_name: str,
+        tls_certificate_path: Optional[str],
+        tls_private_key_path: Optional[str],
+        **kwargs: Any,
+    ) -> str:
         """If the TLS paths are not specified the default will be certs in the
         config directory"""
 
diff --git a/synapse/config/tracer.py b/synapse/config/tracer.py
index 7aff618ea6..3472a9a01b 100644
--- a/synapse/config/tracer.py
+++ b/synapse/config/tracer.py
@@ -12,8 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Set
+from typing import Any, Set
 
+from synapse.types import JsonDict
 from synapse.util.check_dependencies import DependencyException, check_requirements
 
 from ._base import Config, ConfigError
@@ -22,7 +23,7 @@ from ._base import Config, ConfigError
 class TracerConfig(Config):
     section = "tracing"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         opentracing_config = config.get("opentracing")
         if opentracing_config is None:
             opentracing_config = {}
@@ -65,7 +66,7 @@ class TracerConfig(Config):
                 )
             self.force_tracing_for_users.add(u)
 
-    def generate_config_section(cls, **kwargs):
+    def generate_config_section(cls, **kwargs: Any) -> str:
         return """\
         ## Opentracing ##
 
diff --git a/synapse/config/user_directory.py b/synapse/config/user_directory.py
index 6d6678c7e4..010e791924 100644
--- a/synapse/config/user_directory.py
+++ b/synapse/config/user_directory.py
@@ -12,6 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any
+
+from synapse.types import JsonDict
+
 from ._base import Config
 
 
@@ -22,7 +26,7 @@ class UserDirectoryConfig(Config):
 
     section = "userdirectory"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         user_directory_config = config.get("user_directory") or {}
         self.user_directory_search_enabled = user_directory_config.get("enabled", True)
         self.user_directory_search_all_users = user_directory_config.get(
@@ -32,7 +36,7 @@ class UserDirectoryConfig(Config):
             "prefer_local_users", False
         )
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """
         # User Directory configuration
         #
diff --git a/synapse/config/voip.py b/synapse/config/voip.py
index b313bff140..87c09abe24 100644
--- a/synapse/config/voip.py
+++ b/synapse/config/voip.py
@@ -12,13 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Any
+
+from synapse.types import JsonDict
+
 from ._base import Config
 
 
 class VoipConfig(Config):
     section = "voip"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.turn_uris = config.get("turn_uris", [])
         self.turn_shared_secret = config.get("turn_shared_secret")
         self.turn_username = config.get("turn_username")
@@ -28,7 +32,7 @@ class VoipConfig(Config):
         )
         self.turn_allow_guests = config.get("turn_allow_guests", True)
 
-    def generate_config_section(self, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         ## TURN ##
 
diff --git a/synapse/config/workers.py b/synapse/config/workers.py
index bdaba6db37..a5479dfca9 100644
--- a/synapse/config/workers.py
+++ b/synapse/config/workers.py
@@ -14,10 +14,12 @@
 # limitations under the License.
 
 import argparse
-from typing import List, Union
+from typing import Any, List, Union
 
 import attr
 
+from synapse.types import JsonDict
+
 from ._base import (
     Config,
     ConfigError,
@@ -110,7 +112,7 @@ class WorkerConfig(Config):
 
     section = "worker"
 
-    def read_config(self, config, **kwargs):
+    def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         self.worker_app = config.get("worker_app")
 
         # Canonicalise worker_app so that master always has None
@@ -120,9 +122,13 @@ class WorkerConfig(Config):
         self.worker_listeners = [
             parse_listener_def(x) for x in config.get("worker_listeners", [])
         ]
-        self.worker_daemonize = config.get("worker_daemonize")
+        self.worker_daemonize = bool(config.get("worker_daemonize"))
         self.worker_pid_file = config.get("worker_pid_file")
-        self.worker_log_config = config.get("worker_log_config")
+
+        worker_log_config = config.get("worker_log_config")
+        if worker_log_config is not None and not isinstance(worker_log_config, str):
+            raise ConfigError("worker_log_config must be a string")
+        self.worker_log_config = worker_log_config
 
         # The host used to connect to the main synapse
         self.worker_replication_host = config.get("worker_replication_host", None)
@@ -290,7 +296,7 @@ class WorkerConfig(Config):
             self.worker_name is None and background_tasks_instance == "master"
         ) or self.worker_name == background_tasks_instance
 
-    def generate_config_section(self, config_dir_path, server_name, **kwargs):
+    def generate_config_section(self, **kwargs: Any) -> str:
         return """\
         ## Workers ##
 
diff --git a/synapse/handlers/ui_auth/checkers.py b/synapse/handlers/ui_auth/checkers.py
index 014754a630..472b029af3 100644
--- a/synapse/handlers/ui_auth/checkers.py
+++ b/synapse/handlers/ui_auth/checkers.py
@@ -107,6 +107,8 @@ class RecaptchaAuthChecker(UserInteractiveAuthChecker):
         # TODO: get this from the homeserver rather than creating a new one for
         # each request
         try:
+            assert self._secret is not None
+
             resp_body = await self._http_client.post_urlencoded_get_json(
                 self._url,
                 args={
diff --git a/tests/config/test_registration_config.py b/tests/config/test_registration_config.py
index 2acdb6ac61..33d7b70e32 100644
--- a/tests/config/test_registration_config.py
+++ b/tests/config/test_registration_config.py
@@ -37,7 +37,9 @@ class RegistrationConfigTestCase(ConfigFileTestCase):
                     "session_lifetime": "30m",
                     "nonrefreshable_access_token_lifetime": "31m",
                     **config_dict,
-                }
+                },
+                "",
+                "",
             )
 
         with self.assertRaises(ConfigError):
@@ -46,7 +48,9 @@ class RegistrationConfigTestCase(ConfigFileTestCase):
                     "session_lifetime": "30m",
                     "refreshable_access_token_lifetime": "31m",
                     **config_dict,
-                }
+                },
+                "",
+                "",
             )
 
         with self.assertRaises(ConfigError):
@@ -55,7 +59,9 @@ class RegistrationConfigTestCase(ConfigFileTestCase):
                     "session_lifetime": "30m",
                     "refresh_token_lifetime": "31m",
                     **config_dict,
-                }
+                },
+                "",
+                "",
             )
 
         # Then test all the fine conditions
@@ -64,7 +70,9 @@ class RegistrationConfigTestCase(ConfigFileTestCase):
                 "session_lifetime": "31m",
                 "nonrefreshable_access_token_lifetime": "31m",
                 **config_dict,
-            }
+            },
+            "",
+            "",
         )
 
         HomeServerConfig().parse_config_dict(
@@ -72,11 +80,15 @@ class RegistrationConfigTestCase(ConfigFileTestCase):
                 "session_lifetime": "31m",
                 "refreshable_access_token_lifetime": "31m",
                 **config_dict,
-            }
+            },
+            "",
+            "",
         )
 
         HomeServerConfig().parse_config_dict(
-            {"session_lifetime": "31m", "refresh_token_lifetime": "31m", **config_dict}
+            {"session_lifetime": "31m", "refresh_token_lifetime": "31m", **config_dict},
+            "",
+            "",
         )
 
     def test_refuse_to_start_if_open_registration_and_no_verification(self):
diff --git a/tests/config/test_server.py b/tests/config/test_server.py
index b6f21294ba..1f27a54701 100644
--- a/tests/config/test_server.py
+++ b/tests/config/test_server.py
@@ -35,7 +35,7 @@ class ServerConfigTestCase(unittest.TestCase):
     def test_unsecure_listener_no_listeners_open_private_ports_false(self):
         conf = yaml.safe_load(
             ServerConfig().generate_config_section(
-                "che.org", "/data_dir_path", False, None, config_dir_path="CONFDIR"
+                "CONFDIR", "/data_dir_path", "che.org", False, None
             )
         )
 
@@ -55,7 +55,7 @@ class ServerConfigTestCase(unittest.TestCase):
     def test_unsecure_listener_no_listeners_open_private_ports_true(self):
         conf = yaml.safe_load(
             ServerConfig().generate_config_section(
-                "che.org", "/data_dir_path", True, None, config_dir_path="CONFDIR"
+                "CONFDIR", "/data_dir_path", "che.org", True, None
             )
         )
 
@@ -89,7 +89,7 @@ class ServerConfigTestCase(unittest.TestCase):
 
         conf = yaml.safe_load(
             ServerConfig().generate_config_section(
-                "this.one.listens", "/data_dir_path", True, listeners, "CONFDIR"
+                "CONFDIR", "/data_dir_path", "this.one.listens", True, listeners
             )
         )
 
@@ -123,7 +123,7 @@ class ServerConfigTestCase(unittest.TestCase):
 
         conf = yaml.safe_load(
             ServerConfig().generate_config_section(
-                "this.one.listens", "/data_dir_path", True, listeners, "CONFDIR"
+                "CONFDIR", "/data_dir_path", "this.one.listens", True, listeners
             )
         )