diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..69fe9b2
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,15 @@
+name: Test
+on: [push, pull_request]
+jobs:
+  test:
+    runs-on: ubuntu-22.04
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ['3.8', '3.10', '3.11', '3.14.6']
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - run: python -m unittest discover -s tests -v
diff --git a/codewars_unittest/test_result.py b/codewars_unittest/test_result.py
index 5bf1116..104bc4e 100644
--- a/codewars_unittest/test_result.py
+++ b/codewars_unittest/test_result.py
@@ -53,6 +53,20 @@ def addFailure(self, test, err):
         )
         super(CodewarsTestResult, self).addFailure(test, err)
 
+    def addSubTest(self, test, subtest, err):
+        # Keep unittest's own outcome bookkeeping (including failfast) exactly
+        # once. Successful subtests still produce the parent test's one pass.
+        super(CodewarsTestResult, self).addSubTest(test, subtest, err)
+        if err is None:
+            return
+        failure = issubclass(err[0], test.failureException)
+        marker = 'FAILED' if failure else 'ERROR'
+        self.stream.writeln('\n<{}::>Subtest {}'.format(marker, esc(str(subtest))))
+        self.stream.writeln('\n<LOG:ESC:{}>'.format('Failure' if failure else 'Error')
+                            + esc(''.join(traceback.format_exception_only(err[0], err[1]))))
+        self.stream.writeln('\n<LOG:ESC:Traceback>'
+                            + esc(self._exc_info_to_string(err, subtest)))
+
     # from unittest/result.py
     def _exc_info_to_string(self, err, test):
         exctype, value, tb = err
diff --git a/tests/test_subtests.py b/tests/test_subtests.py
new file mode 100644
index 0000000..8e0a3d4
--- /dev/null
+++ b/tests/test_subtests.py
@@ -0,0 +1,80 @@
+import io
+import re
+import unittest
+
+from codewars_unittest import CodewarsTestRunner
+
+
+class TestSubtests(unittest.TestCase):
+    def run_case(self, body):
+        case = type('Example', (unittest.TestCase,), {'test_example': body})
+        stream = io.StringIO()
+        result = CodewarsTestRunner(stream=stream).run(
+            unittest.defaultTestLoader.loadTestsFromTestCase(case))
+        output = stream.getvalue()
+        markers = re.findall(r'^<(PASSED|FAILED|ERROR)::>', output, re.MULTILINE)
+        self.assertEqual(output.count('<IT::>'), 1)
+        self.assertEqual(output.count('<COMPLETEDIN::>'), 2)
+        self.assertEqual(result.testsRun, 1)
+        return result, output, markers
+
+    def test_failed_subtests_emit_failures_and_continue(self):
+        def body(case):
+            for number in (1, 2):
+                with case.subTest(number=number):
+                    case.assertEqual(number, 0)
+        result, output, markers = self.run_case(body)
+        self.assertFalse(result.wasSuccessful())
+        self.assertEqual(len(result.failures), 2)
+        self.assertEqual(markers, ['FAILED', 'FAILED'])
+        self.assertIn('number=1', output)
+        self.assertIn('number=2', output)
+        self.assertIn('<LOG:ESC:Traceback>', output)
+
+    def test_error_subtest_emits_error(self):
+        def body(case):
+            with case.subTest(name='broken'):
+                raise ValueError('child error')
+        result, output, markers = self.run_case(body)
+        self.assertFalse(result.wasSuccessful())
+        self.assertEqual(len(result.errors), 1)
+        self.assertEqual(markers, ['ERROR'])
+        self.assertIn('ValueError: child error', output)
+
+    def test_successful_subtests_keep_one_parent_pass(self):
+        def body(case):
+            for number in (1, 2):
+                with case.subTest(number=number):
+                    case.assertTrue(number)
+        result, _, markers = self.run_case(body)
+        self.assertTrue(result.wasSuccessful())
+        self.assertEqual(markers, ['PASSED'])
+
+    def test_nested_subtest_failure_is_not_duplicated(self):
+        def body(case):
+            with case.subTest(outer=1):
+                with case.subTest(inner=2):
+                    case.fail('original failure')
+        result, output, markers = self.run_case(body)
+        self.assertEqual(len(result.failures), 1)
+        self.assertEqual(markers, ['FAILED'])
+        self.assertIn('outer=1', output)
+        self.assertIn('inner=2', output)
+
+    def test_multiline_messages_cannot_add_protocol_events(self):
+        def body(case):
+            with case.subTest(name='café\n<ERROR::>literal'):
+                case.fail('message\n<PASSED::>literal')
+        _, output, markers = self.run_case(body)
+        self.assertEqual(markers, ['FAILED'])
+        self.assertIn('<:LF:><PASSED::>literal', output)
+
+    def test_regular_tests_keep_existing_reporting(self):
+        result, _, markers = self.run_case(lambda case: case.assertEqual(1, 1))
+        self.assertTrue(result.wasSuccessful())
+        self.assertEqual(markers, ['PASSED'])
+
+    def test_regular_failure_remains_failure(self):
+        result, _, markers = self.run_case(lambda case: case.assertEqual(1, 2))
+        self.assertFalse(result.wasSuccessful())
+        self.assertEqual(markers, ['FAILED'])