diff --git a/py/selenium/webdriver/firefox/extension_connection.py b/py/selenium/webdriver/firefox/extension_connection.py
index df2cbeb4109d6..c3b8e4d2a4723 100644
--- a/py/selenium/webdriver/firefox/extension_connection.py
+++ b/py/selenium/webdriver/firefox/extension_connection.py
@@ -72,7 +72,7 @@ def connect_and_quit(self):
     @classmethod
     def is_connectable(self):
         """Trys to connect to the extension but do not retrieve context."""
-        utils.is_connectable(self.port)
+        utils.is_connectable(self.profile.port)
 
 class ExtensionConnectionError(Exception):
     """An internal error occurred int the extension.