diff --git a/test/test_config_ip.py b/test/test_config_ip.py
index 2bdba53..b7d3010 100644
--- a/test/test_config_ip.py
+++ b/test/test_config_ip.py
@@ -7,7 +7,7 @@ from tiramisu.option import IPOption, NetworkOption, NetmaskOption, \
 
 def test_ip():
     a = IPOption('a', '')
-    b = IPOption('b', '', only_private=True)
+    b = IPOption('b', '', private_only=True)
     od = OptionDescription('od', '', [a, b])
     c = Config(od)
     c.a = '192.168.1.1'
diff --git a/tiramisu/option.py b/tiramisu/option.py
index df4839a..f9a3541 100644
--- a/tiramisu/option.py
+++ b/tiramisu/option.py
@@ -756,15 +756,15 @@ class SymLinkOption(BaseOption):
 
 class IPOption(Option):
     "represents the choice of an ip"
-    __slots__ = ('_only_private', '_allow_reserved')
+    __slots__ = ('_private_only', '_allow_reserved')
     _opt_type = 'ip'
 
     def __init__(self, name, doc, default=None, default_multi=None,
                  requires=None, multi=False, callback=None,
                  callback_params=None, validator=None, validator_params=None,
-                 properties=None, only_private=False, allow_reserved=False,
+                 properties=None, private_only=False, allow_reserved=False,
                  warnings_only=False):
-        self._only_private = only_private
+        self._private_only = private_only
         self._allow_reserved = allow_reserved
         super(IPOption, self).__init__(name, doc, default=default,
                                        default_multi=default_multi,
@@ -787,7 +787,7 @@ class IPOption(Option):
         ip = IP('{0}/32'.format(value))
         if not self._allow_reserved and ip.iptype() == 'RESERVED':
             raise ValueError(_("IP mustn't not be in reserved class"))
-        if self._only_private and not ip.iptype() == 'PRIVATE':
+        if self._private_only and not ip.iptype() == 'PRIVATE':
             raise ValueError(_("IP must be in private class"))