diff --git a/django_slowtests/testrunner.py b/django_slowtests/testrunner.py
index 7600b70..ccbfbf3 100644
--- a/django_slowtests/testrunner.py
+++ b/django_slowtests/testrunner.py
@@ -246,16 +246,16 @@ def suite_result(self, suite, result):
             # Filter tests by threshold
             test_results = []
 
-            for result in by_time:
+            for timing in by_time:
                 # Convert test time from seconds to miliseconds for comparison
-                result_time_ms = result[1] * 1000
+                result_time_ms = timing[1] * 1000
 
                 # If the test was under the threshold
                 # don't show it to the user
                 if result_time_ms < SLOW_TEST_THRESHOLD_MS:
                     continue
 
-                test_results.append(result)
+                test_results.append(timing)
 
         self.generate_report(test_results, result)
         return return_value
diff --git a/django_slowtests/tests/tests.py b/django_slowtests/tests/tests.py
index 452c4cc..fd0aadb 100644
--- a/django_slowtests/tests/tests.py
+++ b/django_slowtests/tests/tests.py
@@ -1,7 +1,8 @@
-from django.test import TestCase
+from django.test import TestCase, override_settings
+from django.test.runner import DiscoverRunner
 from mock import patch
 from unittest import TestResult
-from ..testrunner import TimingSuite
+from ..testrunner import DiscoverSlowestTestsRunner, TimingSuite
 
 
 class TimingSuiteTests(TestCase):
@@ -45,3 +46,24 @@ def test_timing_is_correct_when_freezegun_sets_time_in_future(self):
         self.assertEqual(mock.call_args_list[0][0][0], test_name)
         self.assertTrue(mock.call_args_list[0][0][1] > 0)
         self.assertTrue(mock.call_args_list[0][0][1] < 1)
+
+
+class SuiteResultTests(TestCase):
+    @override_settings(SLOW_TEST_THRESHOLD_MS=100000, ALWAYS_GENERATE_SLOW_REPORT=False)
+    def test_result_object_is_not_replaced_when_threshold_filtering_runs(self):
+        # Regression test: suite_result used to iterate `for result in by_time`,
+        # which shadowed the `result` TestResult argument with a (name, duration)
+        # tuple and crashed generate_report with
+        # AttributeError: 'tuple' object has no attribute 'testsRun'.
+        runner = DiscoverSlowestTestsRunner(generate_report=True)
+        result = TestResult()
+        result.testsRun = 3
+
+        with patch.object(DiscoverRunner, 'suite_result', return_value=0), \
+                patch.object(runner, 'get_timings', return_value=[('slow_test', 0.5)]), \
+                patch.object(runner, 'generate_report') as mock_generate_report:
+            runner.suite_result(suite=None, result=result)
+
+        mock_generate_report.assert_called_once()
+        _, passed_result = mock_generate_report.call_args[0]
+        self.assertIs(passed_result, result)