diff --git a/Lib/shutil.py b/Lib/shutil.py
--- a/Lib/shutil.py
+++ b/Lib/shutil.py
@@ -37,17 +37,18 @@ except ImportError:
     getgrnam = None
 
 __all__ = ["copyfileobj", "copyfile", "copymode", "copystat", "copy", "copy2",
            "copytree", "move", "rmtree", "Error", "SpecialFileError",
            "ExecError", "make_archive", "get_archive_formats",
            "register_archive_format", "unregister_archive_format",
            "get_unpack_formats", "register_unpack_format",
            "unregister_unpack_format", "unpack_archive",
-           "ignore_patterns", "chown", "which"]
+           "ignore_patterns", "chown", "which", "get_terminal_size",
+           "SameFileError"]
            # disk_usage is added later, if available on the platform
 
 class Error(OSError):
     pass
 
 class SameFileError(Error):
     """Raised when source and destination are the same file."""
 
diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py
--- a/Lib/test/test_shutil.py
+++ b/Lib/test/test_shutil.py
@@ -1783,10 +1783,28 @@ class TermsizeTests(unittest.TestCase):
         with support.EnvironmentVarGuard() as env:
             del env['LINES']
             del env['COLUMNS']
             actual = shutil.get_terminal_size()
 
         self.assertEqual(expected, actual)
 
 
+class PublicAPITests(unittest.TestCase):
+    """Ensures that the correct values are exposed in the public API."""
+
+    def test_module_all_attribute(self):
+        self.assertTrue(hasattr(shutil, '__all__'))
+        target_api = ['copyfileobj', 'copyfile', 'copymode', 'copystat',
+                      'copy', 'copy2', 'copytree', 'move', 'rmtree', 'Error',
+                      'SpecialFileError', 'ExecError', 'make_archive',
+                      'get_archive_formats', 'register_archive_format',
+                      'unregister_archive_format', 'get_unpack_formats',
+                      'register_unpack_format', 'unregister_unpack_format',
+                      'unpack_archive', 'ignore_patterns', 'chown', 'which',
+                      'get_terminal_size', 'SameFileError']
+        if hasattr(os, 'statvfs') or os.name == 'nt':
+            target_api.append('disk_usage')
+        self.assertEqual(set(shutil.__all__), set(target_api))
+
+
 if __name__ == '__main__':
     unittest.main()