diff --git a/django_q/cluster.py b/django_q/cluster.py
index f7332fb..5803e89 100644
--- a/django_q/cluster.py
+++ b/django_q/cluster.py
@@ -149,7 +149,7 @@ class Sentinel(object):
         if not self.start_event.is_set() and not self.stop_event.is_set():
             return Conf.STARTING
         elif self.start_event.is_set() and not self.stop_event.is_set():
-            if self.result_queue.qsize() == 0 and self.task_queue.qsize() == 0:
+            if Conf.QSIZE and self.result_queue.qsize() == 0 and self.task_queue.qsize() == 0:
                 return Conf.IDLE
             return Conf.WORKING
         elif self.stop_event.is_set() and self.start_event.is_set():
diff --git a/django_q/conf.py b/django_q/conf.py
index a2b3517..0b68759 100644
--- a/django_q/conf.py
+++ b/django_q/conf.py
@@ -1,6 +1,6 @@
 import logging
 from signal import signal
-from multiprocessing import cpu_count
+from multiprocessing import cpu_count, Queue
 
 from django.utils.translation import ugettext_lazy as _
 from django.conf import settings
@@ -63,6 +63,12 @@ class Conf(object):
     # The redis stats key
     Q_STAT = 'django_q:{}:cluster'.format(PREFIX)
 
+    # OSX doesn't implement qsize because of missing sem_getvalue()
+    try:
+        QSIZE = Queue().qsize == 0
+    except NotImplementedError:
+        QSIZE = False
+
     # Getting the signal names
     SIGNAL_NAMES = dict((getattr(signal, n), n) for n in dir(signal) if n.startswith('SIG') and '_' not in n)
 
diff --git a/django_q/monitor.py b/django_q/monitor.py
index 92bd7ff..3b001c1 100644
--- a/django_q/monitor.py
+++ b/django_q/monitor.py
@@ -117,10 +117,13 @@ class Stat(Status):
         self.reincarnations = sentinel.reincarnations
         self.sentinel = sentinel.pid
         self.status = sentinel.status()
-        self.done_q_size = sentinel.result_queue.qsize()
+        self.done_q_size = 0
+        self.task_q_size = 0
+        if Conf.QSIZE:
+            self.done_q_size = sentinel.result_queue.qsize()
+            self.task_q_size = sentinel.task_queue.qsize()
         if sentinel.monitor:
             self.monitor = sentinel.monitor.pid
-        self.task_q_size = sentinel.task_queue.qsize()
         if sentinel.pusher:
             self.pusher = sentinel.pusher.pid
         self.workers = [w.pid for w in sentinel.pool]
diff --git a/django_q/tests/test_cluster.py b/django_q/tests/test_cluster.py
index 684bb86..7d956b6 100644
--- a/django_q/tests/test_cluster.py
+++ b/django_q/tests/test_cluster.py
@@ -55,7 +55,8 @@ def test_cluster_initial(r):
     assert c.is_starting is False
     sleep(0.5)
     stat = c.stat
-    assert stat.status == Conf.IDLE
+    if Conf.QSIZE:
+        assert stat.status == Conf.IDLE
     assert c.stop() is True
     assert c.sentinel.is_alive() is False
     assert c.has_stopped