diff --git a/MANIFEST.in b/MANIFEST.in
index 67a93b5..adce23c 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,6 +1,7 @@
 include requirements.txt
 include test-requirements.txt
 include README.md
+include bitter/VERSION
 graft bitter/templates
 graft bitter/static
 graft test
diff --git a/bitter/VERSION b/bitter/VERSION
new file mode 100644
index 0000000..167b000
--- /dev/null
+++ b/bitter/VERSION
@@ -0,0 +1 @@
+0.5.4
\ No newline at end of file
diff --git a/bitter/__init__.py b/bitter/__init__.py
index f1552bd..1ef9dc4 100644
--- a/bitter/__init__.py
+++ b/bitter/__init__.py
@@ -3,8 +3,15 @@ Bitter module. A library and cli for Twitter using python-twitter.
 http://github.com/balkian/bitter
 """
 
-from future.standard_library import install_aliases
-install_aliases()
+try:
+    from future.standard_library import install_aliases
+    install_aliases()
+except ImportError:
+    # Avoid problems at setup.py and py3.x
+    pass
+
+import os
+
+from .version import __version__
 
-__version__ = '0.5.0'
 __all__ = ['cli', 'config', 'crawlers', 'models', 'utils' ]
diff --git a/bitter/crawlers.py b/bitter/crawlers.py
index fc2122b..59f2976 100644
--- a/bitter/crawlers.py
+++ b/bitter/crawlers.py
@@ -8,6 +8,7 @@ logger = logging.getLogger(__name__)
 
 from twitter import *
 from collections import OrderedDict
+from threading import Lock
 from . import utils
 from . import config
 
@@ -41,6 +42,7 @@ class TwitterWorker(object):
         self.name = name
         self.client = client
         self.throttled_time = False
+        self._lock = Lock()
         self.busy = False
 
     @property
@@ -76,6 +78,7 @@ class TwitterQueue(AttrToFunc):
             c = None
             try:
                 c = self.next()
+                c._lock.acquire()
                 c.busy = True
                 logger.debug('Next: {}'.format(c.name))
                 ping = time.time()
@@ -97,6 +100,7 @@ class TwitterQueue(AttrToFunc):
             finally:
                 if c:
                     c.busy = False
+                    c._lock.release()
                     
 
     @property
diff --git a/bitter/version.py b/bitter/version.py
new file mode 100644
index 0000000..8d3f7ec
--- /dev/null
+++ b/bitter/version.py
@@ -0,0 +1,4 @@
+import os
+
+with open(os.path.join(os.path.dirname(__file__), 'VERSION')) as f:
+    __version__ = f.read().strip()
diff --git a/requirements-py2.txt b/requirements-py2.txt
index 03fdf8e..55cf629 100644
--- a/requirements-py2.txt
+++ b/requirements-py2.txt
@@ -1 +1,2 @@
 contextlib2
+future
diff --git a/requirements.txt b/requirements.txt
index 3096c17..63537f8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,3 @@
 sqlalchemy
 twitter
 click
-future
diff --git a/setup.py b/setup.py
index d295ac3..890042d 100644
--- a/setup.py
+++ b/setup.py
@@ -23,16 +23,12 @@ if sys.version_info <= (3, 0):
 install_reqs = [str(ir.req) for ir in install_reqs]
 test_reqs = [str(ir.req) for ir in test_reqs]
 
-with open('bitter/__init__.py') as f:
-    exec(f.read())
+from bitter import __version__
 
 setup(
     name="bitter",
     packages=['bitter'],
-    description='''
-    Simplifying how researchers access Data.
-    It includes a CLI and a library.
-    ''',
+    description=" Simplifying how researchers access Data. It includes a CLI and a library.",
     author='J. Fernando Sanchez',
     author_email='balkian@gmail.com',
     url="http://balkian.com",