diff --git a/tools/wptrunner/wptrunner/executors/base.py b/tools/wptrunner/wptrunner/executors/base.py
index 0eef3e3cfe86721..a55eb337264c38f 100644
--- a/tools/wptrunner/wptrunner/executors/base.py
+++ b/tools/wptrunner/wptrunner/executors/base.py
@@ -763,7 +763,7 @@ def process_action(self, url, payload):
                     # AttributeError got an obj property in Python 3.10, for older versions we
                     # fall back to looking at the error message.
                     if ((hasattr(e, "obj") and getattr(e, "obj") == self.protocol) or
-                            f"'{self.protocol.__class__.__name__}' object has no attribute" in str(e)):
+                        f"'{self.protocol.__class__.__name__}' object has no attribute" in str(e)):
                         raise NotImplementedError from e
                     raise
         except self.unimplemented_exc:
diff --git a/tools/wptrunner/wptrunner/executors/executorwebdriver.py b/tools/wptrunner/wptrunner/executors/executorwebdriver.py
index 758c85a01dd0ce7..066eb6f045130b6 100644
--- a/tools/wptrunner/wptrunner/executors/executorwebdriver.py
+++ b/tools/wptrunner/wptrunner/executors/executorwebdriver.py
@@ -126,7 +126,7 @@ async def unsubscribe(self, events):
         self.logger.info("Unsubscribing from events %s" % events)
         return await self.webdriver.bidi_session.session.unsubscribe(events=events, contexts=None)
 
-    def add_event_listener(self, fn, event):
+    def add_event_listener(self, fn, event=None):
         print("adding event listener %s" % event)
         return self.webdriver.bidi_session.add_event_listener(name=event, fn=fn)