diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index f46f8d561ca..f8504564db2 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -584,7 +584,10 @@ class BuiltinTest(unittest.TestCase):
                 raise frozendict_error("frozendict is readonly")
 
         # read-only builtins
-        frozen_builtins = frozendict(__builtins__)
+        if isinstance(__builtins__, types.ModuleType):
+            frozen_builtins = frozendict(__builtins__.__dict__)
+        else:
+            frozen_builtins = frozendict(__builtins__)
         code = compile("__builtins__['superglobal']=2; print(superglobal)", "test", "exec")
         self.assertRaises(frozendict_error,
                           exec, code, {'__builtins__': frozen_builtins})