diff --git a/shep/persist.py b/shep/persist.py
index ac82d55..b814f18 100644
--- a/shep/persist.py
+++ b/shep/persist.py
@@ -17,8 +17,8 @@ class PersistedState(State):
     :type logger: object
     """
 
-    def __init__(self, factory, bits, logger=None, verifier=None):
-        super(PersistedState, self).__init__(bits, logger=logger, verifier=verifier)
+    def __init__(self, factory, bits, logger=None, verifier=None, check_alias=True, event_callback=None):
+        super(PersistedState, self).__init__(bits, logger=logger, verifier=verifier, check_alias=check_alias, event_callback=event_callback)
         self.__store_factory = factory
         self.__stores = {}
 
diff --git a/shep/state.py b/shep/state.py
index 8b216f1..8879eff 100644
--- a/shep/state.py
+++ b/shep/state.py
@@ -203,7 +203,7 @@ class State:
         self.__set(k, v)
 
 
-    def all(self):
+    def all(self, pure=False):
         """Return list of all unique atomic and alias states.
         
         :rtype: list of ints
@@ -215,6 +215,10 @@ class State:
                 continue
             if k.upper() != k:
                 continue
+            if pure:
+                state = self.from_name(k)
+                if not self.__is_pure(state):
+                    continue
             l.append(k)
         l.sort()
         return l
@@ -349,7 +353,7 @@ class State:
             raise StateItemNotFound(key)
 
         new_state = self.__reverse.get(to_state)
-        if new_state == None:
+        if new_state == None and self.check_alias:
             raise StateInvalid(to_state)
 
         return self.__move(key, current_state, to_state)
@@ -549,7 +553,7 @@ class State:
             state = 1
         else:
             state <<= 1
-        if state > self.__c:
+        if state > self.__limit:
             raise StateInvalid('unknown state {}'.format(state))
 
         return state
diff --git a/shep/store/file.py b/shep/store/file.py
index 854dc70..4bc99a9 100644
--- a/shep/store/file.py
+++ b/shep/store/file.py
@@ -27,7 +27,10 @@ class SimpleFileStore:
         """
         fp = os.path.join(self.__path, k)
         if contents == None:
-            contents = ''
+            if self.__m[1] == 'wb':
+                contents = b''
+            else:
+                contents = ''
 
         f = open(fp, self.__m[1])
         f.write(contents)
diff --git a/tests/test_file.py b/tests/test_file.py
index 79b900f..025e6da 100644
--- a/tests/test_file.py
+++ b/tests/test_file.py
@@ -200,6 +200,9 @@ class TestStateReport(unittest.TestCase):
         self.states.next('abcd')
         self.assertEqual(self.states.state('abcd'), self.states.BAR)
 
+        self.states.next('abcd')
+        self.assertEqual(self.states.state('abcd'), self.states.BAZ)
+
         with self.assertRaises(StateInvalid):
             self.states.next('abcd')
 
@@ -207,7 +210,7 @@ class TestStateReport(unittest.TestCase):
         with self.assertRaises(FileNotFoundError):
             os.stat(fp)
 
-        fp = os.path.join(self.d, 'BAR', 'abcd')
+        fp = os.path.join(self.d, 'BAZ', 'abcd')
         os.stat(fp)
 
 
diff --git a/tests/test_state.py b/tests/test_state.py
index e80db73..cf24c37 100644
--- a/tests/test_state.py
+++ b/tests/test_state.py
@@ -48,11 +48,12 @@ class TestState(unittest.TestCase):
 
 
     def test_limit(self):
-        states = State(2)
+        states = State(3)
         states.add('foo')
         states.add('bar')
+        states.add('baz')
         with self.assertRaises(OverflowError):
-            states.add('baz')
+            states.add('gaz')
 
 
     def test_dup(self):
@@ -122,7 +123,7 @@ class TestState(unittest.TestCase):
 
 
     def test_peek(self):
-        states = State(3)
+        states = State(2)
         states.add('foo')
         states.add('bar')
 
@@ -135,7 +136,7 @@ class TestState(unittest.TestCase):
         states.move('abcd', states.BAR)
 
         with self.assertRaises(StateInvalid):
-            self.assertEqual(states.peek('abcd'))
+            states.peek('abcd')
 
 
     def test_from_name(self):