diff --git a/Lib/test/test_largefile.py b/Lib/test/test_largefile.py
--- a/Lib/test/test_largefile.py
+++ b/Lib/test/test_largefile.py
@@ -5,8 +5,7 @@
 import stat
 import sys
 import unittest
-from test.support import run_unittest, TESTFN, verbose, requires, \
-                              unlink
+from test.support import TESTFN, verbose, requires, unlink, use_resources
 import io  # C implementation of io
 import _pyio as pyio # Python implementation of io
 
@@ -23,7 +22,7 @@
 size = 2500000000
 
 
-class LargeFileTest(unittest.TestCase):
+class LargeFileTest:
     """Test that each file function works as expected for a large
     (i.e. > 2GB, do  we have to check > 4GB) files.
 
@@ -103,8 +102,6 @@
         if verbose:
             print('try truncate')
         with self.open(TESTFN, 'r+b') as f:
-            # this is already decided before start running the test suite
-            # but we do it anyway for extra protection
             if not hasattr(f, 'truncate'):
                 raise unittest.SkipTest("open().truncate() not available on this system")
             f.seek(0, 2)
@@ -141,8 +138,7 @@
                 f.seek(pos)
                 self.assertTrue(f.seekable())
 
-
-def test_main():
+def setUpModule():
     # On Windows and Mac OSX this test comsumes large resources; It
     # takes a long time to build the >2GB file and takes >2GB of disk
     # space therefore the resource must be enabled to run this test.
@@ -168,25 +164,26 @@
             raise unittest.SkipTest("filesystem does not have largefile support")
         else:
             f.close()
+
+def load_tests(*args):
+    # Order of tests is important, so add them explicitly
     suite = unittest.TestSuite()
     for _open, prefix in [(io.open, 'C'), (pyio.open, 'Py')]:
-        class TestCase(LargeFileTest):
-            pass
-        TestCase.open = staticmethod(_open)
-        TestCase.__name__ = prefix + LargeFileTest.__name__
+        TestCase = type(prefix + LargeFileTest.__name__,
+                        (LargeFileTest, unittest.TestCase),
+                        {'open': staticmethod(_open)})
         suite.addTest(TestCase('test_seek'))
         suite.addTest(TestCase('test_osstat'))
         suite.addTest(TestCase('test_seek_read'))
         suite.addTest(TestCase('test_lseek'))
-        with _open(TESTFN, 'wb') as f:
-            if hasattr(f, 'truncate'):
-                suite.addTest(TestCase('test_truncate'))
+        suite.addTest(TestCase('test_truncate'))
         suite.addTest(TestCase('test_seekable'))
-        unlink(TESTFN)
-    try:
-        run_unittest(suite)
-    finally:
-        unlink(TESTFN)
+
+    return suite
+
+def tearDownModule():
+    unlink(TESTFN)
 
 if __name__ == '__main__':
-    test_main()
+    use_resources = ['largefile']
+    unittest.main()