Index: Queue.py
===================================================================
--- Queue.py	(revision 60910)
+++ Queue.py	(working copy)
@@ -20,6 +20,8 @@
     If maxsize is <= 0, the queue size is infinite.
     """
     def __init__(self, maxsize=0):
+        if not isinstance(maxsize, int):
+            raise ValueError('maxsize should be an integer')
         try:
             import threading
         except ImportError:
Index: test/test_queue.py
===================================================================
--- test/test_queue.py	(revision 60910)
+++ test/test_queue.py	(working copy)
@@ -189,6 +189,8 @@
         self.simple_queue_test(q)
         self.simple_queue_test(q)
 
+    def test_maxsize_type_check(self):
+        self.assertRaises(ValueError, self.type2test, 'a')
 
 class QueueTest(BaseQueueTest):
     type2test = Queue.Queue