diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 6373e51..02e8fdd 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,15 @@
 CHANGELOG
 =========
 
+UNRELEASED
+----------
+
+*UNRELEASED*
+
+* Fix ``self.instance._outcome`` is ``None`` case in #173 (`#174`_).
+
+.. _#174: https://github.com/pytest-dev/pytest-subtests/pull/174
+
 0.14.0
 ------
 
diff --git a/src/pytest_subtests/plugin.py b/src/pytest_subtests/plugin.py
index 316e1c0..969285a 100644
--- a/src/pytest_subtests/plugin.py
+++ b/src/pytest_subtests/plugin.py
@@ -105,8 +105,10 @@ def _addSkip(self: TestCaseFunction, testcase: TestCase, reason: str) -> None:
             self.addSubTest(testcase.test_case, testcase, exc_info)  # type: ignore[attr-defined]
     else:
         # For python < 3.11: the non-subtest skips have to be added by `_originaladdSkip` only after all subtest
-        # failures are processed by `_addSubTest`.
-        if sys.version_info < (3, 11):
+        # failures are processed by `_addSubTest`. (`self.instance._outcome` has no attribute `skipped/errors` anymore.)
+        # For python < 3.11, we also need to check if `self.instance._outcome` is `None` (this happens if the test
+        # class/method is decorated with `unittest.skip`, see #173).
+        if sys.version_info < (3, 11) and self.instance._outcome is not None:
             subtest_errors = [
                 x
                 for x, y in self.instance._outcome.errors
diff --git a/tests/test_subtests.py b/tests/test_subtests.py
index 8ec97bf..299db77 100644
--- a/tests/test_subtests.py
+++ b/tests/test_subtests.py
@@ -336,6 +336,34 @@ def test_foo(self):
                 ["collected 1 item", "* 3 xfailed, 1 passed in *"]
             )
 
+    @pytest.mark.parametrize("runner", ["pytest-normal"])
+    def test_only_original_skip_is_called(
+        self,
+        pytester: pytest.Pytester,
+        monkeypatch: pytest.MonkeyPatch,
+        runner: Literal["pytest-normal"],
+    ) -> None:
+        """Regression test for #173."""
+        monkeypatch.setenv("COLUMNS", "200")
+        p = pytester.makepyfile(
+            """
+            import unittest
+            from unittest import TestCase, main
+
+            @unittest.skip("skip this test")
+            class T(unittest.TestCase):
+                def test_foo(self):
+                    assert 1 == 2
+
+            if __name__ == '__main__':
+                main()
+        """
+        )
+        result = pytester.runpytest(p, "-v", "-rsf")
+        result.stdout.fnmatch_lines(
+            ["SKIPPED [1] test_only_original_skip_is_called.py:6: skip this test"]
+        )
+
     @pytest.mark.parametrize("runner", ["unittest", "pytest-normal", "pytest-xdist"])
     def test_skip_with_failure(
         self,