diff --git a/testing/firefox-ui/harness/firefox_ui_harness/runners/update.py b/testing/firefox-ui/harness/firefox_ui_harness/runners/update.py
index b8a00409c40e..017b977cfdc3 100644
--- a/testing/firefox-ui/harness/firefox_ui_harness/runners/update.py
+++ b/testing/firefox-ui/harness/firefox_ui_harness/runners/update.py
@@ -105,4 +105,4 @@ class UpdateTestRunner(FirefoxUITestRunner):
         # If exceptions happened, re-throw the last one
         if self.exc_info:
             ex_type, exception, tb = self.exc_info
-            raise ex_type, exception, tb
+            raise ex_type(exception).with_traceback(tb)
diff --git a/tools/lint/py3.yml b/tools/lint/py3.yml
index b1c9626e9e61..5e112c316de4 100644
--- a/tools/lint/py3.yml
+++ b/tools/lint/py3.yml
@@ -25,7 +25,6 @@ py3:
         - security/manager/ssl
         - servo
         - testing/awsy
-        - testing/firefox-ui/harness/firefox_ui_harness/runners/update.py
         - testing/mochitest
         - testing/mozharness
         - testing/raptor