diff --git a/pupy/network/lib/ack.py b/pupy/network/lib/ack.py
index c6d46afc..024e414e 100644
--- a/pupy/network/lib/ack.py
+++ b/pupy/network/lib/ack.py
@@ -21,27 +21,20 @@ from time import time, sleep
 class Ack(object):
     """ Dumb (and fast, and unsafe) event replacement """
 
-    __slots__ = ( '_lock', '_is_set', '_wait_lock' )
+    __slots__ = ( '_lock', '_is_set', '_wait_lock'  )
 
     def __init__(self):
         self._lock = Lock()
-        self._is_set = False
+        self._is_set = None
         self._wait_lock = None
 
-    def clear(self):
-        with self._lock:
-            if self._is_set is None and self._wait_lock:
-                self._wait_lock.release()
-
-            self._is_set = False
-
     def is_set(self):
         with self._lock:
             return self._is_set is True
 
     def set(self):
         with self._lock:
-            if self._is_set is None and self._wait_lock:
+            if self._is_set is False and self._wait_lock:
                 self._wait_lock.release()
 
             self._is_set = True
@@ -51,18 +44,18 @@ class Ack(object):
             with self._lock:
                 if self._is_set:
                     return True
-                else:
-                    self._is_set = None
+
+                elif self._is_set is None:
+                    self._is_set = False
                     self._wait_lock = Lock()
                     self._wait_lock.acquire()
 
+                else:
+                    raise ValueError('Already in wait state!')
+
             self._wait_lock.acquire()
 
             with self._lock:
-                if self._is_set is False:
-                    # Cleared
-                    self._wait_lock.release()
-
                 self._wait_lock = None
                 return self._is_set is True
 
@@ -81,7 +74,7 @@ class Ack(object):
                 delay = min(timeout, probe, delay*2)
 
                 with self._lock:
-                    if self._is_set is True:
+                    if self._is_set:
                         return True
 
             return False
diff --git a/pupy/network/lib/buffer.py b/pupy/network/lib/buffer.py
index c483a58c..9cd3c057 100644
--- a/pupy/network/lib/buffer.py
+++ b/pupy/network/lib/buffer.py
@@ -12,8 +12,7 @@ __all__ = (
 import sys
 import zlib
 
-from threading import Lock
-from .ack import Ack
+from threading import Lock, Event
 
 DEFAULT_FORCED_FLUSH_BUFFER_SIZE = 32768
 DEFAULT_MAX_STR_SIZE = 4096
@@ -33,7 +32,7 @@ class Buffer(object):
     ALLOW_BUFFER_AS_DATA = True
 
     def __init__(self, data='', on_write=None, transport_func=None, truncate=False,
-                 chunk_size=None, compressed=False):
+                 chunk_size=None, compressed=False, shared=False):
         """
         Initialize a buffer with 'data'.
         """
@@ -44,7 +43,7 @@ class Buffer(object):
 
         self.on_write_f = on_write
         self.data_lock = Lock()
-        self.waiting = Ack()
+        self.waiting = Event() if shared else None
         self.transport = transport_func
         self.cookie = None
         self.chunk_size = None
@@ -78,19 +77,26 @@ class Buffer(object):
         if self.on_write_f:
             self.on_write_f()
 
-        self.waiting.set()
+        if self.waiting:
+            self.waiting.set()
 
     def wait(self, timeout=0.1):
         """ wait for a size """
+
         if self._len > 0:
             return True
-        else:
+        elif self.waiting is not None:
             self.waiting.clear()
+        else:
+            raise ValueError('Bufer should be shared to use wait()')
 
         self.waiting.wait(timeout)
         return self._len > 0
 
     def wake(self):
+        if not self.waiting:
+            raise ValueError('Bufer should be shared to use wake()')
+
         self.waiting.set()
 
     def _linearize(self, upto=None):