diff --git a/test/new_api/test_slots.py b/test/new_api/test_slots.py
new file mode 100644
index 0000000..e9df6e7
--- /dev/null
+++ b/test/new_api/test_slots.py
@@ -0,0 +1,171 @@
+## coding: utf-8
+from .autopath import do_autopath
+do_autopath()
+
+from py.test import raises
+
+from tiramisu.setting import ConfigBag
+from tiramisu.config import Config, SubConfig
+from tiramisu.option import ChoiceOption, BoolOption, IntOption, FloatOption,\
+    StrOption, SymLinkOption, UnicodeOption, IPOption, OptionDescription, \
+    PortOption, NetworkOption, NetmaskOption, DomainnameOption, EmailOption, \
+    URLOption, FilenameOption
+
+
+def test_slots_option():
+    c = ChoiceOption('a', '', ('a',))
+    raises(AttributeError, "c.x = 1")
+    c = BoolOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = IntOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = FloatOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = StrOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = SymLinkOption('b', c)
+    raises(AttributeError, "c.x = 1")
+    c = UnicodeOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = IPOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = OptionDescription('a', '', [])
+    raises(AttributeError, "c.x = 1")
+    c = PortOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = NetworkOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = NetmaskOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = DomainnameOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = EmailOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = URLOption('a', '')
+    raises(AttributeError, "c.x = 1")
+    c = FilenameOption('a', '')
+    raises(AttributeError, "c.x = 1")
+
+
+def test_slots_option_readonly():
+    a = ChoiceOption('a', '', ('a',))
+    b = BoolOption('b', '')
+    c = IntOption('c', '')
+    d = FloatOption('d', '')
+    e = StrOption('e', '')
+    g = UnicodeOption('g', '')
+    h = IPOption('h', '')
+    i = PortOption('i', '')
+    j = NetworkOption('j', '')
+    k = NetmaskOption('k', '')
+    l = DomainnameOption('l', '')
+    o = EmailOption('o', '')
+    p = URLOption('p', '')
+    q = FilenameOption('q', '')
+    m = OptionDescription('m', '', [a, b, c, d, e, g, h, i, j, k, l, o, p, q])
+    a._requires = (((a,),),)
+    b._requires = (((a,),),)
+    c._requires = (((a,),),)
+    d._requires = (((a,),),)
+    e._requires = (((a,),),)
+    g._requires = (((a,),),)
+    h._requires = (((a,),),)
+    i._requires = (((a,),),)
+    j._requires = (((a,),),)
+    k._requires = (((a,),),)
+    l._requires = (((a,),),)
+    m._requires = (((a,),),)
+    o._requires = (((a,),),)
+    p._requires = (((a,),),)
+    q._requires = (((a,),),)
+    Config(m)
+    raises(AttributeError, "a._requires = 'a'")
+    raises(AttributeError, "b._requires = 'b'")
+    raises(AttributeError, "c._requires = 'c'")
+    raises(AttributeError, "d._requires = 'd'")
+    raises(AttributeError, "e._requires = 'e'")
+    raises(AttributeError, "g._requires = 'g'")
+    raises(AttributeError, "h._requires = 'h'")
+    raises(AttributeError, "i._requires = 'i'")
+    raises(AttributeError, "j._requires = 'j'")
+    raises(AttributeError, "k._requires = 'k'")
+    raises(AttributeError, "l._requires = 'l'")
+    raises(AttributeError, "m._requires = 'm'")
+    raises(AttributeError, "o._requires = 'o'")
+    raises(AttributeError, "p._requires = 'p'")
+    raises(AttributeError, "q._requires = 'q'")
+
+
+def test_slots_option_readonly_name():
+    a = ChoiceOption('a', '', ('a',))
+    b = BoolOption('b', '')
+    c = IntOption('c', '')
+    d = FloatOption('d', '')
+    e = StrOption('e', '')
+    f = SymLinkOption('f', c)
+    g = UnicodeOption('g', '')
+    h = IPOption('h', '')
+    i = PortOption('i', '')
+    j = NetworkOption('j', '')
+    k = NetmaskOption('k', '')
+    l = DomainnameOption('l', '')
+    o = DomainnameOption('o', '')
+    p = DomainnameOption('p', '')
+    q = DomainnameOption('q', '')
+    m = OptionDescription('m', '', [a, b, c, d, e, f, g, h, i, j, k, l, o, p, q])
+    m
+    raises(AttributeError, "a._name = 'a'")
+    raises(AttributeError, "b._name = 'b'")
+    raises(AttributeError, "c._name = 'c'")
+    raises(AttributeError, "d._name = 'd'")
+    raises(AttributeError, "e._name = 'e'")
+    raises(AttributeError, "f._name = 'f'")
+    raises(AttributeError, "g._name = 'g'")
+    raises(AttributeError, "h._name = 'h'")
+    raises(AttributeError, "i._name = 'i'")
+    raises(AttributeError, "j._name = 'j'")
+    raises(AttributeError, "k._name = 'k'")
+    raises(AttributeError, "l._name = 'l'")
+    raises(AttributeError, "m._name = 'm'")
+    raises(AttributeError, "o._name = 'o'")
+    raises(AttributeError, "p._name = 'p'")
+    raises(AttributeError, "q._name = 'q'")
+
+
+#def test_slots_description():
+#    # __slots__ for OptionDescription should be complete for __getattr__
+#    slots = set()
+#    for subclass in OptionDescription.__mro__:
+#        if subclass is not object:
+#            slots.update(subclass.__slots__)
+#    assert slots == set(OptionDescription.__slots__)
+
+
+def test_slots_config():
+    od1 = OptionDescription('a', '', [])
+    od2 = OptionDescription('a', '', [od1])
+    c = Config(od2)
+    raises(AttributeError, "c.x = 1")
+    raises(AttributeError, "c.cfgimpl_x = 1")
+    sc = c.getattr('a', None, ConfigBag(c))
+    assert isinstance(sc, SubConfig)
+    raises(AttributeError, "sc.x = 1")
+    raises(AttributeError, "sc.cfgimpl_x = 1")
+
+
+def test_slots_setting():
+    od1 = OptionDescription('a', '', [])
+    od2 = OptionDescription('a', '', [od1])
+    c = Config(od2)
+    s = c.cfgimpl_get_settings()
+    s
+    raises(AttributeError, "s.x = 1")
+
+
+def test_slots_value():
+    od1 = OptionDescription('a', '', [])
+    od2 = OptionDescription('a', '', [od1])
+    c = Config(od2)
+    v = c.cfgimpl_get_values()
+    v
+    raises(AttributeError, "v.x = 1")