diff --git a/pyproject.toml b/pyproject.toml
index db9823d..874996b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,6 +37,7 @@ test = [
 	"pytest-ignore-flaky",
 	"jaraco.test",
 	"importlib_resources; python_version < '3.9'",
+	"pytest-timeout",
 ]
 
 doc = [
diff --git a/tests/test_path.py b/tests/test_path.py
index 273ede1..4571c00 100644
--- a/tests/test_path.py
+++ b/tests/test_path.py
@@ -586,6 +586,7 @@ def test_getinfo_missing(self, alpharep):
             alpharep.getinfo('does-not-exist')
 
     @pytest.mark.xfail(reason="python/cpython#123270")
+    @pytest.mark.timeout(1)
     def test_malformed_paths(self):
         """
         Path should handle malformed paths.
@@ -604,7 +605,6 @@ def test_malformed_paths(self):
         ]
         assert root.joinpath('..').joinpath('parent.txt').read_bytes() == b'content'
 
-    @pytest.mark.xfail(reason="python/cpython#123270")
     def test_unsupported_names(self):
         """
         Path segments with special characters are readable.
@@ -624,7 +624,6 @@ def test_unsupported_names(self):
         assert next(contents).name == 'V: NMS.flac'
         assert root.joinpath('V: NMS.flac').read_bytes() == b"fLaC..."
 
-    @pytest.mark.xfail(reason="python/cpython#123270")
     def test_backslash_not_separator(self):
         """
         In a zip file, backslashes are not separators.
diff --git a/zipp/__init__.py b/zipp/__init__.py
index 10e9540..051bfc9 100644
--- a/zipp/__init__.py
+++ b/zipp/__init__.py
@@ -95,69 +95,7 @@ def __setstate__(self, state):
         super().__init__(*args, **kwargs)
 
 
-class SanitizedNames:
-    """
-    ZipFile mix-in to ensure names are sanitized.
-    """
-
-    def namelist(self):
-        return list(map(self._sanitize, super().namelist()))
-
-    @staticmethod
-    def _sanitize(name):
-        r"""
-        Ensure a relative path with posix separators and no dot names.
-
-        Modeled after
-        https://github.com/python/cpython/blob/bcc1be39cb1d04ad9fc0bd1b9193d3972835a57c/Lib/zipfile/__init__.py#L1799-L1813
-        but provides consistent cross-platform behavior.
-
-        >>> san = SanitizedNames._sanitize
-        >>> san('/foo/bar')
-        'foo/bar'
-        >>> san('//foo.txt')
-        'foo.txt'
-        >>> san('foo/.././bar.txt')
-        'foo/bar.txt'
-        >>> san('foo../.bar.txt')
-        'foo../.bar.txt'
-        >>> san('\\foo\\bar.txt')
-        'foo/bar.txt'
-        >>> san('D:\\foo.txt')
-        'D/foo.txt'
-        >>> san('\\\\server\\share\\file.txt')
-        'server/share/file.txt'
-        >>> san('\\\\?\\GLOBALROOT\\Volume3')
-        '?/GLOBALROOT/Volume3'
-        >>> san('\\\\.\\PhysicalDrive1\\root')
-        'PhysicalDrive1/root'
-
-        Retain any trailing slash.
-        >>> san('abc/')
-        'abc/'
-
-        Raises a ValueError if the result is empty.
-        >>> san('../..')
-        Traceback (most recent call last):
-        ...
-        ValueError: Empty filename
-        """
-
-        def allowed(part):
-            return part and part not in {'..', '.'}
-
-        # Remove the drive letter.
-        # Don't use ntpath.splitdrive, because that also strips UNC paths
-        bare = re.sub('^([A-Z]):', r'\1', name, flags=re.IGNORECASE)
-        clean = bare.replace('\\', '/')
-        parts = clean.split('/')
-        joined = '/'.join(filter(allowed, parts))
-        if not joined:
-            raise ValueError("Empty filename")
-        return joined + '/' * name.endswith('/')
-
-
-class CompleteDirs(InitializedState, SanitizedNames, zipfile.ZipFile):
+class CompleteDirs(InitializedState, zipfile.ZipFile):
     """
     A ZipFile subclass that ensures that implied directories
     are always included in the namelist.