diff --git a/Lib/test/test_glob.py b/Lib/test/test_glob.py
--- a/Lib/test/test_glob.py
+++ b/Lib/test/test_glob.py
@@ -4,12 +4,14 @@
 import sys
 import unittest
 
-from test.support import (run_unittest, TESTFN, skip_unless_symlink,
+from test.support import (TESTFN, skip_unless_symlink,
                           can_symlink, create_empty_file)
 
 
 class GlobTests(unittest.TestCase):
 
+    sep = os.sep
+
     def norm(self, *parts):
         return os.path.normpath(os.path.join(self.tempdir, *parts))
 
@@ -117,24 +119,24 @@
         # either of these results is reasonable
         self.assertIn(set(res), [
                       {self.norm('aaa'), self.norm('aab')},
-                      {self.norm('aaa') + os.sep, self.norm('aab') + os.sep},
+                      {self.norm('aaa') + self.sep, self.norm('aab') + self.sep},
                       ])
 
     def test_glob_bytes_directory_with_trailing_slash(self):
         # Same as test_glob_directory_with_trailing_slash, but with a
         # bytes argument.
-        res = glob.glob(os.fsencode(self.norm('Z*Z') + os.sep))
+        res = glob.glob(os.fsencode(self.norm('Z*Z') + self.sep))
         self.assertEqual(res, [])
-        res = glob.glob(os.fsencode(self.norm('ZZZ') + os.sep))
+        res = glob.glob(os.fsencode(self.norm('ZZZ') + self.sep))
         self.assertEqual(res, [])
-        res = glob.glob(os.fsencode(self.norm('aa*') + os.sep))
+        res = glob.glob(os.fsencode(self.norm('aa*') + self.sep))
         self.assertEqual(len(res), 2)
         # either of these results is reasonable
         self.assertIn(set(res), [
                       {os.fsencode(self.norm('aaa')),
                        os.fsencode(self.norm('aab'))},
-                      {os.fsencode(self.norm('aaa') + os.sep),
-                       os.fsencode(self.norm('aab') + os.sep)},
+                      {os.fsencode(self.norm('aaa') + self.sep),
+                       os.fsencode(self.norm('aab') + self.sep)},
                       ])
 
     @skip_unless_symlink
@@ -144,7 +146,7 @@
         eq(self.glob('sym3', '*'), [self.norm('sym3', 'EF'),
                                     self.norm('sym3', 'efg')])
         self.assertIn(self.glob('sym3' + os.sep),
-                      [[self.norm('sym3')], [self.norm('sym3') + os.sep]])
+                      [[self.norm('sym3')], [self.norm('sym3') + self.sep]])
         eq(self.glob('*', '*F'),
            [self.norm('aaa', 'zzzF'),
             self.norm('aab', 'F'), self.norm('sym3', 'EF')])
@@ -170,9 +172,31 @@
         eq(glob.glob(b'\\\\*\\*\\'), [])
 
 
-def test_main():
-    run_unittest(GlobTests)
+class GlobBytesTests(GlobTests):
+
+    sep = bytes(os.sep, 'ASCII')
+
+    def norm(self, *parts):
+        return bytes(os.path.normpath(os.path.join(
+                     self.tempdir, *parts)), 'ASCII')
+
+    def glob(self, *parts):
+        if len(parts) == 1:
+            pattern = parts[0]
+        else:
+            pattern = os.path.join(*parts)
+        p = bytes(os.path.join(self.tempdir, pattern), 'ASCII')
+        res = glob.glob(p)
+        self.assertEqual(list(glob.iglob(p)), res)
+        return res
+
+    def test_glob_directory_with_trailing_slash(self):
+        # This test doesn't use self.glob/norm, override for bytes.
+        res = glob.glob(bytes(self.tempdir + '*' + os.sep, 'ASCII'))
+        self.assertEqual(len(res), 1)
+        self.assertIn(res[0], [bytes(self.tempdir, 'ASCII'),
+                               bytes(self.tempdir + os.sep, 'ASCII')])
 
 
 if __name__ == "__main__":
-    test_main()
+    unittest.main()