diff --git a/py/selenium/webdriver/chromium/service.py b/py/selenium/webdriver/chromium/service.py
index 9f50e21e8e36f..74045feb2521d 100644
--- a/py/selenium/webdriver/chromium/service.py
+++ b/py/selenium/webdriver/chromium/service.py
@@ -49,7 +49,7 @@ def __init__(
 
         if isinstance(log_output, str):
             self.service_args.append(f"--log-path={log_output}")
-            self.log_output: Optional[IOBase] = None
+            self.log_output: cast(IOBase, None)
         elif isinstance(log_output, IOBase):
             self.log_output = log_output
         else:
diff --git a/py/selenium/webdriver/chromium/webdriver.py b/py/selenium/webdriver/chromium/webdriver.py
index 4dcf8d73e8fe0..f525d34317d6e 100644
--- a/py/selenium/webdriver/chromium/webdriver.py
+++ b/py/selenium/webdriver/chromium/webdriver.py
@@ -33,10 +33,12 @@ def __init__(
         self,
         browser_name: Optional[str] = None,
         vendor_prefix: Optional[str] = None,
-        options: ArgOptions = ArgOptions(),
+        options: ArgOptions = None,
         service: Optional[Service] = None,
         keep_alive: bool = True,
     ) -> None:
+        if options is None:
+            options = ArgOptions()
         """Creates a new WebDriver instance of the ChromiumDriver. Starts the
         service and then creates new WebDriver instance of ChromiumDriver.
 
@@ -49,6 +51,9 @@ def __init__(
         """
         self.service = service
 
+        if self.service is None:
+            raise ValueError("Service must be provided and cannot be None")
+
         finder = DriverFinder(self.service, options)
         if finder.get_browser_path():
             options.binary_location = finder.get_browser_path()
@@ -59,8 +64,8 @@ def __init__(
 
         executor = ChromiumRemoteConnection(
             remote_server_addr=self.service.service_url,
-            browser_name=browser_name,
-            vendor_prefix=vendor_prefix,
+            browser_name=browser_name or "",
+            vendor_prefix=vendor_prefix or "",
             keep_alive=keep_alive,
             ignore_proxy=options._ignore_local_proxy,
         )
@@ -221,7 +226,8 @@ def quit(self) -> None:
             # We don't care about the message because something probably has gone wrong
             pass
         finally:
-            self.service.stop()
+            if self.service is not None:
+                self.service.stop()
 
     def download_file(self, *args, **kwargs):
         raise NotImplementedError
diff --git a/py/selenium/webdriver/common/bidi/browser.py b/py/selenium/webdriver/common/bidi/browser.py
index ce697051bef44..52229037d8de7 100644
--- a/py/selenium/webdriver/common/bidi/browser.py
+++ b/py/selenium/webdriver/common/bidi/browser.py
@@ -125,13 +125,13 @@ def from_dict(cls, data: dict) -> "ClientWindowInfo":
             ClientWindowInfo: A new instance of ClientWindowInfo.
         """
         return cls(
-            client_window=data.get("clientWindow"),
-            state=data.get("state"),
-            width=data.get("width"),
-            height=data.get("height"),
-            x=data.get("x"),
-            y=data.get("y"),
-            active=data.get("active"),
+            client_window=str(data.get("clientWindow")),
+            state=str(data.get("state")),
+            width=int(data.get("width") or 0),
+            height=int(data.get("height") or 0),
+            x=int(data.get("x") or 0),
+            y=int(data.get("y") or 0),
+            active=bool(data.get("active")),
         )
 
 
diff --git a/py/selenium/webdriver/common/bidi/browsing_context.py b/py/selenium/webdriver/common/bidi/browsing_context.py
index e843752b7a27f..55e62aaf9f153 100644
--- a/py/selenium/webdriver/common/bidi/browsing_context.py
+++ b/py/selenium/webdriver/common/bidi/browsing_context.py
@@ -15,7 +15,7 @@
 # specific language governing permissions and limitations
 # under the License.
 
-from typing import Optional, Union
+from typing import Optional, Union, Callable
 
 from selenium.webdriver.common.bidi.common import command_builder
 
@@ -67,10 +67,10 @@ def from_json(cls, json: dict) -> "NavigationInfo":
             NavigationInfo: A new instance of NavigationInfo.
         """
         return cls(
-            context=json.get("context"),
+            context=str(json.get("context")),
             navigation=json.get("navigation"),
-            timestamp=json.get("timestamp"),
-            url=json.get("url"),
+            timestamp=int(json.get("timestamp") or 0),
+            url=str(json.get("url")),
         )
 
 
@@ -109,11 +109,11 @@ def from_json(cls, json: dict) -> "BrowsingContextInfo":
         """
         children = None
         if json.get("children") is not None:
-            children = [BrowsingContextInfo.from_json(child) for child in json.get("children")]
+            children = [BrowsingContextInfo.from_json(child) for child in json.get("children", [])]
 
         return cls(
-            context=json.get("context"),
-            url=json.get("url"),
+            context=str(json.get("context")),
+            url=str(json.get("url")),
             children=children,
             parent=json.get("parent"),
             user_context=json.get("userContext"),
@@ -149,11 +149,11 @@ def from_json(cls, json: dict) -> "DownloadWillBeginParams":
             DownloadWillBeginParams: A new instance of DownloadWillBeginParams.
         """
         return cls(
-            context=json.get("context"),
+            context=str(json.get("context")),
             navigation=json.get("navigation"),
-            timestamp=json.get("timestamp"),
-            url=json.get("url"),
-            suggested_filename=json.get("suggestedFilename"),
+            timestamp=int(json.get("timestamp") or 0),
+            url=str(json.get("url")),
+            suggested_filename=str(json.get("suggestedFilename")),
         )
 
 
@@ -187,10 +187,10 @@ def from_json(cls, json: dict) -> "UserPromptOpenedParams":
             UserPromptOpenedParams: A new instance of UserPromptOpenedParams.
         """
         return cls(
-            context=json.get("context"),
-            handler=json.get("handler"),
-            message=json.get("message"),
-            type=json.get("type"),
+            context=str(json.get("context")),
+            handler=str(json.get("handler")),
+            message=str(json.get("message")),
+            type=str(json.get("type")),
             default_value=json.get("defaultValue"),
         )
 
@@ -223,9 +223,9 @@ def from_json(cls, json: dict) -> "UserPromptClosedParams":
             UserPromptClosedParams: A new instance of UserPromptClosedParams.
         """
         return cls(
-            context=json.get("context"),
-            accepted=json.get("accepted"),
-            type=json.get("type"),
+            context=str(json.get("context")),
+            accepted=bool(json.get("accepted")),
+            type=str(json.get("type")),
             user_text=json.get("userText"),
         )
 
@@ -254,8 +254,8 @@ def from_json(cls, json: dict) -> "HistoryUpdatedParams":
             HistoryUpdatedParams: A new instance of HistoryUpdatedParams.
         """
         return cls(
-            context=json.get("context"),
-            url=json.get("url"),
+            context=str(json.get("context")),
+            url=str(json.get("url")),
         )
 
 
@@ -278,7 +278,7 @@ def from_json(cls, json: dict) -> "BrowsingContextEvent":
         -------
             BrowsingContextEvent: A new instance of BrowsingContextEvent.
         """
-        return cls(event_class=json.get("event_class"), **json)
+        return cls(event_class=str(json.get("event_class")), **json)
 
 
 class BrowsingContext:
@@ -341,9 +341,9 @@ def capture_screenshot(
         """
         params = {"context": context, "origin": origin}
         if format is not None:
-            params["format"] = format
+            params["format"] = str(format)
         if clip is not None:
-            params["clip"] = clip
+            params["clip"] = str(clip)
 
         result = self.conn.execute(command_builder("browsingContext.captureScreenshot", params))
         return result["data"]
@@ -387,7 +387,7 @@ def create(
         if reference_context is not None:
             params["referenceContext"] = reference_context
         if background is not None:
-            params["background"] = background
+            params["background"] = str(background)
         if user_context is not None:
             params["userContext"] = user_context
 
@@ -415,7 +415,7 @@ def get_tree(
         if max_depth is not None:
             params["maxDepth"] = max_depth
         if root is not None:
-            params["root"] = root
+            params["root"] = int(root or 0)
 
         result = self.conn.execute(command_builder("browsingContext.getTree", params))
         return [BrowsingContextInfo.from_json(context) for context in result["contexts"]]
@@ -436,7 +436,7 @@ def handle_user_prompt(
         """
         params = {"context": context}
         if accept is not None:
-            params["accept"] = accept
+            params["accept"] = str(accept)
         if user_text is not None:
             params["userText"] = user_text
 
@@ -466,7 +466,7 @@ def locate_nodes(
         """
         params = {"context": context, "locator": locator}
         if max_node_count is not None:
-            params["maxNodeCount"] = max_node_count
+            params["maxNodeCount"] = [int(max_node_count or 0)]
         if serialization_options is not None:
             params["serializationOptions"] = serialization_options
         if start_nodes is not None:
@@ -566,7 +566,7 @@ def reload(
         """
         params = {"context": context}
         if ignore_cache is not None:
-            params["ignoreCache"] = ignore_cache
+            params["ignoreCache"] = str(ignore_cache)
         if wait is not None:
             params["wait"] = wait
 
@@ -597,11 +597,11 @@ def set_viewport(
         if context is not None:
             params["context"] = context
         if viewport is not None:
-            params["viewport"] = viewport
+            params["viewport"] = str(viewport)
         if device_pixel_ratio is not None:
-            params["devicePixelRatio"] = device_pixel_ratio
+            params["devicePixelRatio"] = str(device_pixel_ratio)
         if user_contexts is not None:
-            params["userContexts"] = user_contexts
+            params["userContexts"] = str(user_contexts)
 
         self.conn.execute(command_builder("browsingContext.setViewport", params))
 
@@ -621,7 +621,7 @@ def traverse_history(self, context: str, delta: int) -> dict:
         result = self.conn.execute(command_builder("browsingContext.traverseHistory", params))
         return result
 
-    def _on_event(self, event_name: str, callback: callable) -> int:
+    def _on_event(self, event_name: str, callback: Callable) -> int:
         """Set a callback function to subscribe to a browsing context event.
 
         Parameters:
@@ -665,7 +665,7 @@ def _callback(event_data):
 
         return callback_id
 
-    def add_event_handler(self, event: str, callback: callable, contexts: Optional[list[str]] = None) -> int:
+    def add_event_handler(self, event: str, callback: Callable, contexts: Optional[list[str]] = None) -> int:
         """Add an event handler to the browsing context.
 
         Parameters:
@@ -710,7 +710,7 @@ def remove_event_handler(self, event: str, callback_id: int) -> None:
         except KeyError:
             raise Exception(f"Event {event} not found")
 
-        event = BrowsingContextEvent(event_name)
+        event = str(BrowsingContextEvent(event_name))
 
         self.conn.remove_callback(event, callback_id)
         self.subscriptions[event_name].remove(callback_id)
diff --git a/py/selenium/webdriver/common/bidi/cdp.py b/py/selenium/webdriver/common/bidi/cdp.py
index 6ab3d3b012299..13d5628bbaa15 100644
--- a/py/selenium/webdriver/common/bidi/cdp.py
+++ b/py/selenium/webdriver/common/bidi/cdp.py
@@ -427,6 +427,10 @@ async def connect_session(self, target_id) -> "CdpSession":
         """Returns a new :class:`CdpSession` connected to the specified
         target."""
         global devtools
+        if devtools and devtools.target:
+            session_id = await self.execute(devtools.target.attach_to_target(target_id, True))
+        else:
+            raise RuntimeError("devtools.target is not available.")
         session_id = await self.execute(devtools.target.attach_to_target(target_id, True))
         session = CdpSession(self.ws, session_id, target_id)
         self.sessions[session_id] = session
diff --git a/py/selenium/webdriver/common/bidi/storage.py b/py/selenium/webdriver/common/bidi/storage.py
index 620477aeae6da..5a25f9ccceff7 100644
--- a/py/selenium/webdriver/common/bidi/storage.py
+++ b/py/selenium/webdriver/common/bidi/storage.py
@@ -88,9 +88,9 @@ def from_dict(cls, data: dict) -> "Cookie":
         value = BytesValue(data.get("value", {}).get("type"), data.get("value", {}).get("value"))
 
         return cls(
-            name=data.get("name"),
+            name=str(data.get("name")),
             value=value,
-            domain=data.get("domain"),
+            domain=str(data.get("domain")),
             path=data.get("path"),
             size=data.get("size"),
             http_only=data.get("httpOnly"),
@@ -136,21 +136,21 @@ def to_dict(self) -> dict:
         if self.name is not None:
             result["name"] = self.name
         if self.value is not None:
-            result["value"] = self.value.to_dict()
+            result["value"] = str(self.value.to_dict())
         if self.domain is not None:
             result["domain"] = self.domain
         if self.path is not None:
             result["path"] = self.path
         if self.size is not None:
-            result["size"] = self.size
+            result["size"] = str(self.size)
         if self.http_only is not None:
-            result["httpOnly"] = self.http_only
+            result["httpOnly"] = str(self.http_only)
         if self.secure is not None:
-            result["secure"] = self.secure
+            result["secure"] = str(self.secure)
         if self.same_site is not None:
             result["sameSite"] = self.same_site
         if self.expiry is not None:
-            result["expiry"] = self.expiry
+            result["expiry"] = str(self.expiry)
         return result
 
 
@@ -257,13 +257,13 @@ def to_dict(self) -> dict:
         if self.path is not None:
             result["path"] = self.path
         if self.http_only is not None:
-            result["httpOnly"] = self.http_only
+            result["httpOnly"] = [self.http_only]
         if self.secure is not None:
-            result["secure"] = self.secure
+            result["secure"] = [self.secure]
         if self.same_site is not None:
             result["sameSite"] = self.same_site
         if self.expiry is not None:
-            result["expiry"] = self.expiry
+            result["expiry"] = [self.expiry]
         return result
 
 
diff --git a/py/selenium/webdriver/common/options.py b/py/selenium/webdriver/common/options.py
index 67e5765645133..21d459e42e0af 100644
--- a/py/selenium/webdriver/common/options.py
+++ b/py/selenium/webdriver/common/options.py
@@ -422,7 +422,7 @@ def __init__(self) -> None:
         self._caps = self.default_capabilities
         self._proxy = None
         self.set_capability("pageLoadStrategy", PageLoadStrategy.normal)
-        self.mobile_options = None
+        self.mobile_options: Optional[dict[str, str]] = None
         self._ignore_local_proxy = False
 
     @property
@@ -475,6 +475,7 @@ class ArgOptions(BaseOptions):
     def __init__(self) -> None:
         super().__init__()
         self._arguments: list[str] = []
+        self.binary_location: Optional[str] = None
 
     @property
     def arguments(self):
diff --git a/py/selenium/webdriver/common/service.py b/py/selenium/webdriver/common/service.py
index e03adb6202f84..3e210b66148a3 100644
--- a/py/selenium/webdriver/common/service.py
+++ b/py/selenium/webdriver/common/service.py
@@ -58,12 +58,12 @@ def __init__(
     ) -> None:
         if isinstance(log_output, str):
             self.log_output = cast(IOBase, open(log_output, "a+", encoding="utf-8"))
-        elif log_output == subprocess.STDOUT:
-            self.log_output = cast(Optional[Union[int, IOBase]], None)
-        elif log_output is None or log_output == subprocess.DEVNULL:
-            self.log_output = cast(Optional[Union[int, IOBase]], subprocess.DEVNULL)
-        else:
+        elif log_output in {subprocess.STDOUT, subprocess.DEVNULL, None}:
+            self.log_output = cast(IOBase, subprocess.DEVNULL)
+        elif isinstance(log_output, IOBase):
             self.log_output = log_output
+        else:
+            raise TypeError("log_output must be a string, IOBase, or a valid subprocess constant")
 
         self.port = port or utils.free_port()
         # Default value for every python subprocess: subprocess.Popen(..., creationflags=0)
diff --git a/py/selenium/webdriver/common/utils.py b/py/selenium/webdriver/common/utils.py
index b04e2b0e40c30..11f60d59375b2 100644
--- a/py/selenium/webdriver/common/utils.py
+++ b/py/selenium/webdriver/common/utils.py
@@ -64,13 +64,13 @@ def find_connectable_ip(host: Union[str, bytes, bytearray, None], port: Optional
     for family, _, _, _, sockaddr in addrinfos:
         connectable = True
         if port:
-            connectable = is_connectable(port, sockaddr[0])
+            connectable = is_connectable(port, str(sockaddr[0]))
 
         if connectable and family == socket.AF_INET:
-            return sockaddr[0]
+            return str(sockaddr[0])
         if connectable and not ip and family == socket.AF_INET6:
             ip = sockaddr[0]
-    return ip
+    return str(ip) if ip else None
 
 
 def join_host_port(host: str, port: int) -> str:
@@ -132,7 +132,7 @@ def keys_to_typing(value: Iterable[AnyKey]) -> list[str]:
     for val in value:
         if isinstance(val, Keys):
             # Todo: Does this even work?
-            characters.append(val)
+            characters.append(str(val))
         elif isinstance(val, (int, float)):
             characters.extend(str(val))
         else:
diff --git a/py/selenium/webdriver/common/virtual_authenticator.py b/py/selenium/webdriver/common/virtual_authenticator.py
index a434de83741df..19b0ec615e7c5 100644
--- a/py/selenium/webdriver/common/virtual_authenticator.py
+++ b/py/selenium/webdriver/common/virtual_authenticator.py
@@ -24,17 +24,17 @@
 class Protocol(str, Enum):
     """Protocol to communicate with the authenticator."""
 
-    CTAP2: str = "ctap2"
-    U2F: str = "ctap1/u2f"
+    CTAP2 = "ctap2"
+    U2F = "ctap1/u2f"
 
 
 class Transport(str, Enum):
     """Transport method to communicate with the authenticator."""
 
-    BLE: str = "ble"
-    USB: str = "usb"
-    NFC: str = "nfc"
-    INTERNAL: str = "internal"
+    BLE = "ble"
+    USB = "usb"
+    NFC = "nfc"
+    INTERNAL = "internal"
 
 
 class VirtualAuthenticatorOptions:
diff --git a/py/selenium/webdriver/firefox/remote_connection.py b/py/selenium/webdriver/firefox/remote_connection.py
index a749cce37dc62..8f8019f223613 100644
--- a/py/selenium/webdriver/firefox/remote_connection.py
+++ b/py/selenium/webdriver/firefox/remote_connection.py
@@ -23,7 +23,7 @@
 
 
 class FirefoxRemoteConnection(RemoteConnection):
-    browser_name = DesiredCapabilities.FIREFOX["browserName"]
+    browser_name: str = str(DesiredCapabilities.FIREFOX["browserName"])
 
     def __init__(
         self,
diff --git a/py/selenium/webdriver/remote/remote_connection.py b/py/selenium/webdriver/remote/remote_connection.py
index 7ed47b56275b3..11cbc91e7ac2d 100644
--- a/py/selenium/webdriver/remote/remote_connection.py
+++ b/py/selenium/webdriver/remote/remote_connection.py
@@ -23,6 +23,7 @@
 from typing import Optional
 from urllib import parse
 from urllib.parse import urlparse
+from typing import Any
 
 import urllib3
 
@@ -368,7 +369,7 @@ def __init__(
             self._conn = self._get_connection_manager()
         self._commands = remote_commands
 
-    extra_commands = {}
+    extra_commands: dict[str, Any] = {}
 
     def add_command(self, name, method, url):
         """Register a new command."""
diff --git a/py/selenium/webdriver/remote/webdriver.py b/py/selenium/webdriver/remote/webdriver.py
index 149f12d8fe1a0..302ef3fd36595 100644
--- a/py/selenium/webdriver/remote/webdriver.py
+++ b/py/selenium/webdriver/remote/webdriver.py
@@ -30,7 +30,7 @@
 from base64 import b64decode, urlsafe_b64encode
 from contextlib import asynccontextmanager, contextmanager
 from importlib import import_module
-from typing import Any, Optional, Union
+from typing import Any, Optional, Union, cast
 
 from selenium.common.exceptions import (
     InvalidArgumentException,
@@ -124,7 +124,7 @@ def get_remote_connection(
     handler = next((c for c in candidates if c.browser_name == capabilities.get("browserName")), RemoteConnection)
 
     return handler(
-        remote_server_addr=command_executor,
+        remote_server_addr=str(command_executor),
         keep_alive=keep_alive,
         ignore_proxy=ignore_local_proxy,
         client_config=client_config,
@@ -132,7 +132,7 @@ def get_remote_connection(
 
 
 def create_matches(options: list[BaseOptions]) -> dict:
-    capabilities = {"capabilities": {}}
+    capabilities: dict[str, Any] = {"capabilities": {}}
     opts = []
     for opt in options:
         opts.append(opt.to_capabilities())
@@ -156,8 +156,10 @@ def create_matches(options: list[BaseOptions]) -> dict:
         always[k] = v
 
     for i in opts:
-        for k in always:
-            del i[k]
+        # Ensure `i` is a dictionary before we delete from it
+        if isinstance(i, dict):
+            for k in always:
+                del i[k]
 
     capabilities["capabilities"]["alwaysMatch"] = always
     capabilities["capabilities"]["firstMatch"] = opts
@@ -242,16 +244,19 @@ def __init__(
                 ignore_local_proxy=_ignore_local_proxy,
                 client_config=client_config,
             )
+        if web_element_cls and not issubclass(web_element_cls, WebElement):
+            raise TypeError("web_element_cls must be a subclass of WebElement")
+
         self._is_remote = True
         self.session_id = None
-        self.caps = {}
-        self.pinned_scripts = {}
+        self.caps: dict[str, Any] = {}
+        self.pinned_scripts: dict[str, Any] = {}
         self.error_handler = ErrorHandler()
         self._switch_to = SwitchTo(self)
         self._mobile = Mobile(self)
         self.file_detector = file_detector or LocalFileDetector()
         self.locator_converter = locator_converter or LocatorConverter()
-        self._web_element_cls = web_element_cls or self._web_element_cls
+        self._web_element_cls = cast(type[WebElement], web_element_cls) if web_element_cls else WebElement
         self._authenticator_id = None
         self.start_client()
         self.start_session(capabilities)
@@ -442,7 +447,13 @@ def execute(self, driver_command: str, params: Optional[dict[str, Any]] = None)
             elif "sessionId" not in params:
                 params["sessionId"] = self.session_id
 
-        response = self.command_executor.execute(driver_command, params)
+        # Ensure `self.command_executor` is an instance of `RemoteConnection`
+        # before attempting to call its `execute` method.
+        if isinstance(self.command_executor, RemoteConnection):
+            response = self.command_executor.execute(driver_command, params)
+        else:
+            raise TypeError("command_executor must be an instance of RemoteConnection")
+
         if response:
             self.error_handler.check_response(response)
             response["value"] = self._unwrap_value(response.get("value", None))
@@ -605,7 +616,8 @@ def quit(self) -> None:
             self.execute(Command.QUIT)
         finally:
             self.stop_client()
-            self.command_executor.close()
+            if isinstance(self.command_executor, RemoteConnection):
+                self.command_executor.close()
 
     @property
     def current_window_handle(self) -> str:
@@ -660,9 +672,9 @@ def print_page(self, print_options: Optional[PrintOptions] = None) -> str:
         --------
         >>> driver.print_page()
         """
-        options = {}
+        options: dict[str, Any] = {}
         if print_options:
-            options = print_options.to_dict()
+            options = cast(dict[str, Any], print_options.to_dict())
 
         return self.execute(Command.PRINT_PAGE, options)["value"]
 
@@ -943,8 +955,10 @@ def find_elements(self, by=By.ID, value: Optional[str] = None) -> list[WebElemen
 
         if isinstance(by, RelativeBy):
             _pkg = ".".join(__name__.split(".")[:-1])
-            raw_function = pkgutil.get_data(_pkg, "findElements.js").decode("utf8")
-            find_element_js = f"/* findElements */return ({raw_function}).apply(null, arguments);"
+            raw_function = pkgutil.get_data(_pkg, "findElements.js")
+            if raw_function is None:
+                raise ValueError("Failed to load 'findElements.js' using pkgutil.get_data.")
+            find_element_js = f"/* findElements */return ({raw_function.decode('utf8')}).apply(null, arguments);"
             return self.execute_script(find_element_js, by.to_dict())
 
         # Return empty list if driver returns null
@@ -1404,7 +1418,7 @@ def virtual_authenticator_id(self) -> str:
         --------
         >>> print(driver.virtual_authenticator_id)
         """
-        return self._authenticator_id
+        return self._authenticator_id or ""
 
     @required_virtual_authenticator
     def remove_virtual_authenticator(self) -> None:
diff --git a/py/selenium/webdriver/webkitgtk/service.py b/py/selenium/webdriver/webkitgtk/service.py
index e7f300019c838..bffc9418a4aab 100644
--- a/py/selenium/webdriver/webkitgtk/service.py
+++ b/py/selenium/webdriver/webkitgtk/service.py
@@ -21,7 +21,7 @@
 
 from selenium.webdriver.common import service
 
-DEFAULT_EXECUTABLE_PATH: str = shutil.which("WebKitWebDriver")
+DEFAULT_EXECUTABLE_PATH: Optional[str] = shutil.which("WebKitWebDriver")
 
 
 class Service(service.Service):
diff --git a/py/selenium/webdriver/wpewebkit/service.py b/py/selenium/webdriver/wpewebkit/service.py
index 1f2b244807583..a8c0ef3d54c87 100644
--- a/py/selenium/webdriver/wpewebkit/service.py
+++ b/py/selenium/webdriver/wpewebkit/service.py
@@ -38,7 +38,7 @@ class Service(service.Service):
 
     def __init__(
         self,
-        executable_path: str = DEFAULT_EXECUTABLE_PATH,
+        executable_path: Optional[str] = DEFAULT_EXECUTABLE_PATH,
         port: int = 0,
         log_output: Optional[str] = None,
         service_args: Optional[list[str]] = None,