diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 4405d99..729c0ca 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -293,13 +293,13 @@
     def test_invalid_operations(self):
         # Try writing on a file opened in read mode and vice-versa.
         for mode in ("w", "wb"):
-            with open(support.TESTFN, mode) as fp:
+            with self.open(support.TESTFN, mode) as fp:
                 self.assertRaises(IOError, fp.read)
                 self.assertRaises(IOError, fp.readline)
-        with open(support.TESTFN, "rb") as fp:
+        with self.open(support.TESTFN, "rb") as fp:
             self.assertRaises(IOError, fp.write, b"blah")
             self.assertRaises(IOError, fp.writelines, [b"blah\n"])
-        with open(support.TESTFN, "r") as fp:
+        with self.open(support.TESTFN, "r") as fp:
             self.assertRaises(IOError, fp.write, "blah")
             self.assertRaises(IOError, fp.writelines, ["blah\n"])
 
@@ -370,12 +370,12 @@
     def test_with_open(self):
         for bufsize in (0, 1, 100):
             f = None
-            with open(support.TESTFN, "wb", bufsize) as f:
+            with self.open(support.TESTFN, "wb", bufsize) as f:
                 f.write(b"xxx")
             self.assertEqual(f.closed, True)
             f = None
             try:
-                with open(support.TESTFN, "wb", bufsize) as f:
+                with self.open(support.TESTFN, "wb", bufsize) as f:
                     1/0
             except ZeroDivisionError:
                 self.assertEqual(f.closed, True)
@@ -415,7 +415,7 @@
         del f
         support.gc_collect()
         self.assertEqual(record, [1, 2, 3])
-        with open(support.TESTFN, "rb") as f:
+        with self.open(support.TESTFN, "rb") as f:
             self.assertEqual(f.read(), b"xxx")
 
     def _check_base_destructor(self, base):
@@ -510,7 +510,7 @@
         del f
         support.gc_collect()
         self.assert_(wr() is None, wr)
-        with open(support.TESTFN, "rb") as f:
+        with self.open(support.TESTFN, "rb") as f:
             self.assertEqual(f.read(), b"abcxxx")
 
     def test_unbounded_file(self):
@@ -522,11 +522,11 @@
             self.skipTest("test can only run in a 32-bit address space")
         if support.real_max_memuse < support._2G:
             self.skipTest("test requires at least 2GB of memory")
-        with open(zero, "rb", buffering=0) as f:
+        with self.open(zero, "rb", buffering=0) as f:
             self.assertRaises(OverflowError, f.read)
-        with open(zero, "rb") as f:
+        with self.open(zero, "rb") as f:
             self.assertRaises(OverflowError, f.read)
-        with open(zero, "r") as f:
+        with self.open(zero, "r") as f:
             self.assertRaises(OverflowError, f.read)
 
 class CIOTest(IOTest):
@@ -737,9 +737,9 @@
             l = list(range(256)) * N
             random.shuffle(l)
             s = bytes(bytearray(l))
-            with io.open(support.TESTFN, "wb") as f:
+            with self.open(support.TESTFN, "wb") as f:
                 f.write(s)
-            with io.open(support.TESTFN, self.read_mode, buffering=0) as raw:
+            with self.open(support.TESTFN, self.read_mode, buffering=0) as raw:
                 bufio = self.tp(raw, 8)
                 errors = []
                 results = []
@@ -966,12 +966,12 @@
 
     def test_truncate(self):
         # Truncate implicitly flushes the buffer.
-        with io.open(support.TESTFN, self.write_mode, buffering=0) as raw:
+        with self.open(support.TESTFN, self.write_mode, buffering=0) as raw:
             bufio = self.tp(raw, 8)
             bufio.write(b"abcdef")
             self.assertEqual(bufio.truncate(3), 3)
             self.assertEqual(bufio.tell(), 3)
-        with io.open(support.TESTFN, "rb", buffering=0) as f:
+        with self.open(support.TESTFN, "rb", buffering=0) as f:
             self.assertEqual(f.read(), b"abc")
 
     def test_threads(self):
@@ -993,7 +993,7 @@
             # writing the buffer to the raw streams. This is in addition
             # to concurrency issues due to switching threads in the middle
             # of Python code.
-            with io.open(support.TESTFN, self.write_mode, buffering=0) as raw:
+            with self.open(support.TESTFN, self.write_mode, buffering=0) as raw:
                 bufio = self.tp(raw, 8)
                 errors = []
                 def f():
@@ -1016,7 +1016,7 @@
                 self.assertFalse(errors,
                     "the following exceptions were caught: %r" % errors)
                 bufio.close()
-            with io.open(support.TESTFN, "rb") as f:
+            with self.open(support.TESTFN, "rb") as f:
                 s = f.read()
             for i in range(256):
                 self.assertEquals(s.count(bytes([i])), N)
@@ -1076,7 +1076,7 @@
         del f
         support.gc_collect()
         self.assert_(wr() is None, wr)
-        with open(support.TESTFN, "rb") as f:
+        with self.open(support.TESTFN, "rb") as f:
             self.assertEqual(f.read(), b"123xxx")
 
 
@@ -2055,7 +2055,7 @@
         del t
         support.gc_collect()
         self.assert_(wr() is None, wr)
-        with open(support.TESTFN, "rb") as f:
+        with self.open(support.TESTFN, "rb") as f:
             self.assertEqual(f.read(), b"456def")
 
 class PyTextIOWrapperTest(TextIOWrapperTest):