diff --git a/pre_commit/clientlib.py b/pre_commit/clientlib.py
index 3c086cb9..c94691a5 100644
--- a/pre_commit/clientlib.py
+++ b/pre_commit/clientlib.py
@@ -124,7 +124,7 @@ CONFIG_REPO_DICT = schema.Map(
     schema.Conditional(
         'sha', schema.check_string,
         condition_key='repo',
-        condition_value=schema.NotIn((_LOCAL_SENTINEL, _META_SENTINEL)),
+        condition_value=schema.NotIn(_LOCAL_SENTINEL, _META_SENTINEL),
         ensure_absent=True,
     ),
 )
diff --git a/pre_commit/schema.py b/pre_commit/schema.py
index e85c2303..89e1bcfc 100644
--- a/pre_commit/schema.py
+++ b/pre_commit/schema.py
@@ -201,17 +201,14 @@ class Array(collections.namedtuple('Array', ('of',))):
         return [remove_defaults(val, self.of) for val in v]
 
 
-class Not(object):
-    def __init__(self, val):
-        self.val = val
-
+class Not(collections.namedtuple('Not', ('val',))):
     def __eq__(self, other):
         return other is not MISSING and other != self.val
 
 
-class NotIn(object):
-    def __init__(self, values):
-        self.values = values
+class NotIn(collections.namedtuple('NotIn', ('values',))):
+    def __new__(cls, *values):
+        return super(NotIn, cls).__new__(cls, values=values)
 
     def __eq__(self, other):
         return other is not MISSING and other not in self.values
diff --git a/tests/schema_test.py b/tests/schema_test.py
index 06f28e76..565f7e17 100644
--- a/tests/schema_test.py
+++ b/tests/schema_test.py
@@ -113,7 +113,7 @@ def test_not(val, expected):
     (('bar', True), ('foo', False), (MISSING, False)),
 )
 def test_not_in(values, expected):
-    compared = NotIn(('baz', 'foo'))
+    compared = NotIn('baz', 'foo')
     assert (values == compared) is expected
     assert (compared == values) is expected
 
@@ -211,7 +211,7 @@ map_conditional_absent_not_in = Map(
     'foo', 'key',
     Conditional(
         'key2', check_bool,
-        condition_key='key', condition_value=NotIn((1, 2)), ensure_absent=True,
+        condition_key='key', condition_value=NotIn(1, 2), ensure_absent=True,
     ),
 )