diff --git a/src/functional_tests/base.py b/src/functional_tests/base.py
index fb55841..16f53f2 100644
--- a/src/functional_tests/base.py
+++ b/src/functional_tests/base.py
@@ -1,3 +1,4 @@
+import itertools
 import os
 import time
 
@@ -62,7 +63,9 @@ class FunctionalTest(StaticLiveServerTestCase):
     def _test_has_failed(self):
         return any(
             failure[0] == self
-            for failure in self._outcome.result.failures + self._outcome.result.errors
+            for failure in itertools.chain(
+                self._outcome.result.failures, self._outcome.result.errors
+            )
         )
     
     def take_screenshot(self):
@@ -155,7 +158,9 @@ class ChannelsFunctionalTest(ChannelsLiveServerTestCase):
     def _test_has_failed(self):
         return any(
             failure[0] == self
-            for failure in self._outcome.result.failures + self._outcome.result.errors
+            for failure in itertools.chain(
+                self._outcome.result.failures, self._outcome.result.errors
+            )
         )
 
     def take_screenshot(self):