diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 936dbed..af3b90a 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -29,6 +29,7 @@
 import random
 import unittest
 import weakref
+import warnings
 import abc
 import signal
 import errno
@@ -603,6 +604,20 @@
             fileio.close()
             f2.readline()
 
+    def test_nonbuffered_textio(self):
+        with warnings.catch_warnings(record=True) as recorded:
+            with self.assertRaises(ValueError):
+                self.open(support.TESTFN, 'w', buffering=0)
+            support.gc_collect()
+        self.assertEqual(recorded, [])
+
+    def test_invalid_newline(self):
+        with warnings.catch_warnings(record=True) as recorded:
+            with self.assertRaises(ValueError):
+                self.open(support.TESTFN, 'w', newline='invalid')
+            support.gc_collect()
+        self.assertEqual(recorded, [])
+
 
 class CIOTest(IOTest):