diff --git a/src/calibre/utils/ipc/pool.py b/src/calibre/utils/ipc/pool.py
index a36de998cd..aff69e4354 100644
--- a/src/calibre/utils/ipc/pool.py
+++ b/src/calibre/utils/ipc/pool.py
@@ -6,7 +6,7 @@ from __future__ import (unicode_literals, division, absolute_import,
 __license__ = 'GPL v3'
 __copyright__ = '2014, Kovid Goyal <kovid at kovidgoyal.net>'
 
-import os, cPickle, sys
+import os, sys
 from threading import Thread
 from collections import namedtuple
 from Queue import Queue
@@ -16,6 +16,7 @@ from calibre.constants import iswindows, DEBUG
 from calibre.ptempfile import PersistentTemporaryFile
 from calibre.utils import join_with_timeout
 from calibre.utils.ipc import eintr_retry_call
+from calibre.utils.serialize import msgpack_dumps, msgpack_loads, pickle_dumps, pickle_loads
 
 Job = namedtuple('Job', 'id module func args kwargs')
 Result = namedtuple('Result', 'value err traceback')
@@ -95,7 +96,7 @@ class Worker(object):
         self.name = name or ''
 
     def __call__(self, job):
-        eintr_retry_call(self.conn.send_bytes, cPickle.dumps(job, -1))
+        eintr_retry_call(self.conn.send_bytes, pickle_dumps(job))
         if job is not None:
             self.job_id = job.id
             t = Thread(target=self.recv, name='PoolWorker-'+self.name)
@@ -104,7 +105,7 @@ class Worker(object):
 
     def recv(self):
         try:
-            result = cPickle.loads(eintr_retry_call(self.conn.recv_bytes))
+            result = pickle_loads(eintr_retry_call(self.conn.recv_bytes))
             wr = WorkerResult(self.job_id, result, False, self)
         except Exception as err:
             import traceback
@@ -130,7 +131,7 @@ class Pool(Thread):
         self.results = Queue()
         self.tracker = Queue()
         self.terminal_failure = None
-        self.common_data = cPickle.dumps(None, -1)
+        self.common_data = pickle_dumps(None)
         self.worker_data = None
         self.shutting_down = False
 
@@ -192,7 +193,7 @@ class Pool(Thread):
         p.stdin.flush(), p.stdin.close()
         conn = eintr_retry_call(self.listener.accept)
         w = Worker(p, conn, self.events, self.name)
-        if self.common_data != cPickle.dumps(None, -1):
+        if self.common_data != pickle_dumps(None):
             w.set_common_data(self.common_data)
         return w
 
@@ -211,7 +212,7 @@ class Pool(Thread):
         from calibre.utils.ipc.server import create_listener
         self.auth_key = os.urandom(32)
         self.address, self.listener = create_listener(self.auth_key)
-        self.worker_data = cPickle.dumps((self.address, self.auth_key), -1)
+        self.worker_data = msgpack_dumps((self.address, self.auth_key))
         if self.start_worker() is False:
             return
 
@@ -243,12 +244,12 @@ class Pool(Thread):
                 return False
             self.results.put(worker_result)
         else:
-            self.common_data = cPickle.dumps(event, -1)
+            self.common_data = pickle_dumps(event)
             if len(self.common_data) > MAX_SIZE:
                 self.cd_file = PersistentTemporaryFile('pool_common_data')
                 with self.cd_file as f:
                     f.write(self.common_data)
-                self.common_data = cPickle.dumps(File(f.name), -1)
+                self.common_data = pickle_dumps(File(f.name))
             for worker in self.available_workers:
                 try:
                     worker.set_common_data(self.common_data)
@@ -340,7 +341,7 @@ def worker_main(conn):
     common_data = None
     while True:
         try:
-            job = cPickle.loads(eintr_retry_call(conn.recv_bytes))
+            job = pickle_loads(eintr_retry_call(conn.recv_bytes))
         except EOFError:
             break
         except KeyboardInterrupt:
@@ -354,7 +355,9 @@ def worker_main(conn):
             break
         if not isinstance(job, Job):
             if isinstance(job, File):
-                common_data = cPickle.load(open(job.name, 'rb'))
+                with lopen(job.name, 'rb') as f:
+                    common_data = f.read()
+                common_data = pickle_loads(common_data)
             else:
                 common_data = job
             continue
@@ -374,7 +377,7 @@ def worker_main(conn):
             import traceback
             result = Result(None, as_unicode(err), traceback.format_exc())
         try:
-            eintr_retry_call(conn.send_bytes, cPickle.dumps(result, -1))
+            eintr_retry_call(conn.send_bytes, pickle_dumps(result))
         except EOFError:
             break
         except Exception:
@@ -388,7 +391,8 @@ def worker_main(conn):
 def run_main(func):
     from multiprocessing.connection import Client
     from contextlib import closing
-    address, key = cPickle.loads(eintr_retry_call(sys.stdin.read))
+    stdin = getattr(sys.stdin, 'buffer', sys.stdin)
+    address, key = msgpack_loads(eintr_retry_call(stdin.read))
     with closing(Client(address, authkey=key)) as conn:
         raise SystemExit(func(conn))