1 files changed, 6 insertions, 2 deletions
diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index ec2fbaee32..d5a12a31dd 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -65,9 +65,13 @@ class PosixPathTest(unittest.TestCase):
         with self.assertRaisesRegex(TypeError, errmsg):
             posixpath.join('str', b'bytes')
         # regression, see #15377
-        with self.assertRaises(TypeError) as cm:
+        errmsg = r'join\(\) argument must be str or bytes, not %r'
+        with self.assertRaisesRegex(TypeError, errmsg % 'NoneType'):
             posixpath.join(None, 'str')
-        self.assertNotEqual(cm.exception.args[0], errmsg)
+        with self.assertRaisesRegex(TypeError, errmsg % 'NoneType'):
+            posixpath.join('str', None)
+        with self.assertRaisesRegex(TypeError, errmsg % 'bytearray'):
+            posixpath.join(bytearray(b'foo'), bytearray(b'bar'))
 
     def test_split(self):
         self.assertEqual(posixpath.split("/foo/bar"), ("/foo", "bar"))