diff --git a/Lib/test/test_cmath.py b/Lib/test/test_cmath.py
index 4bdec6d2d83..9fa08dc4ff3 100644
--- a/Lib/test/test_cmath.py
+++ b/Lib/test/test_cmath.py
@@ -192,14 +192,7 @@ def test_user_object(self):
         # end up being passed to the cmath functions
 
         # usual case: new-style class implementing __complex__
-        class MyComplex(object):
-            def __init__(self, value):
-                self.value = value
-            def __complex__(self):
-                return self.value
-
-        # old-style class implementing __complex__
-        class MyComplexOS:
+        class MyComplex:
             def __init__(self, value):
                 self.value = value
             def __complex__(self):
@@ -208,18 +201,13 @@ def __complex__(self):
         # classes for which __complex__ raises an exception
         class SomeException(Exception):
             pass
-        class MyComplexException(object):
-            def __complex__(self):
-                raise SomeException
-        class MyComplexExceptionOS:
+        class MyComplexException:
             def __complex__(self):
                 raise SomeException
 
         # some classes not providing __float__ or __complex__
         class NeitherComplexNorFloat(object):
             pass
-        class NeitherComplexNorFloatOS:
-            pass
         class Index:
             def __int__(self): return 2
             def __index__(self): return 2
@@ -228,48 +216,32 @@ def __int__(self): return 2
 
         # other possible combinations of __float__ and __complex__
         # that should work
-        class FloatAndComplex(object):
+        class FloatAndComplex:
             def __float__(self):
                 return flt_arg
             def __complex__(self):
                 return cx_arg
-        class FloatAndComplexOS:
-            def __float__(self):
-                return flt_arg
-            def __complex__(self):
-                return cx_arg
-        class JustFloat(object):
-            def __float__(self):
-                return flt_arg
-        class JustFloatOS:
+        class JustFloat:
             def __float__(self):
                 return flt_arg
 
         for f in self.test_functions:
             # usual usage
             self.assertEqual(f(MyComplex(cx_arg)), f(cx_arg))
-            self.assertEqual(f(MyComplexOS(cx_arg)), f(cx_arg))
             # other combinations of __float__ and __complex__
             self.assertEqual(f(FloatAndComplex()), f(cx_arg))
-            self.assertEqual(f(FloatAndComplexOS()), f(cx_arg))
             self.assertEqual(f(JustFloat()), f(flt_arg))
-            self.assertEqual(f(JustFloatOS()), f(flt_arg))
             self.assertEqual(f(Index()), f(int(Index())))
             # TypeError should be raised for classes not providing
             # either __complex__ or __float__, even if they provide
-            # __int__ or __index__.  An old-style class
-            # currently raises AttributeError instead of a TypeError;
-            # this could be considered a bug.
+            # __int__ or __index__:
             self.assertRaises(TypeError, f, NeitherComplexNorFloat())
             self.assertRaises(TypeError, f, MyInt())
-            self.assertRaises(Exception, f, NeitherComplexNorFloatOS())
             # non-complex return value from __complex__ -> TypeError
             for bad_complex in non_complexes:
                 self.assertRaises(TypeError, f, MyComplex(bad_complex))
-                self.assertRaises(TypeError, f, MyComplexOS(bad_complex))
             # exceptions in __complex__ should be propagated correctly
             self.assertRaises(SomeException, f, MyComplexException())
-            self.assertRaises(SomeException, f, MyComplexExceptionOS())
 
     def test_input_type(self):
         # ints should be acceptable inputs to all cmath