Fixes Issue #20165: The unittest module no longer considers tests marked with
@expectedFailure successful if they pass.
diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index 5cbc51b..537cc3b 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -1772,6 +1772,10 @@
       Return ``True`` if all tests run so far have passed, otherwise returns
       ``False``.
 
+      .. versionchanged:: 3.4
+         Returns ``False`` if there were any :attr:`unexpectedSuccesses`
+         from tests marked with the :func:`expectedFailure` decorator.
+
 
    .. method:: stop()