diff --git a/py/selenium/webdriver/chrome/options.py b/py/selenium/webdriver/chrome/options.py
index 5fe1cb8b4ce4c..80ef3064c6e84 100644
--- a/py/selenium/webdriver/chrome/options.py
+++ b/py/selenium/webdriver/chrome/options.py
@@ -17,6 +17,7 @@
 
 from selenium.webdriver.chromium.options import ChromiumOptions
 from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
+from typing import Optional
 
 
 class Options(ChromiumOptions):
@@ -25,5 +26,9 @@ class Options(ChromiumOptions):
     def default_capabilities(self) -> dict:
         return DesiredCapabilities.CHROME.copy()
 
-    def enable_mobile(self, android_package="com.android.chrome", android_activity=None, device_serial=None):
+    def enable_mobile(self,
+                      android_package: str = "com.android.chrome",
+                      android_activity: Optional[str] = None,
+                      device_serial: Optional[str] = None
+                      ) -> None:
         super().enable_mobile(android_package, android_activity, device_serial)