Index: Doc/library/threading.rst
===================================================================
--- Doc/library/threading.rst	(revision 73468)
+++ Doc/library/threading.rst	(working copy)
@@ -198,7 +198,7 @@
 A thread can be flagged as a "daemon thread".  The significance of this flag is
 that the entire Python program exits when only daemon threads are left.  The
 initial value is inherited from the creating thread.  The flag can be set
-through the :attr:`daemon` property.
+through the :attr:`daemon` property or by setting the *daemon* argument to True.
 
 There is a "main thread" object; this corresponds to the initial thread of
 control in the Python program.  It is not a daemon thread.
@@ -211,7 +211,8 @@
 impossible to detect the termination of alien threads.
 
 
-.. class:: Thread(group=None, target=None, name=None, args=(), kwargs={})
+.. class:: Thread(group=None, target=None, name=None, args=(), kwargs={},
+            verbose=None, daemon=False)
 
    This constructor should always be called with keyword arguments.  Arguments are:
 
@@ -229,6 +230,10 @@
    *kwargs* is a dictionary of keyword arguments for the target invocation.
    Defaults to ``{}``.
 
+   *verbose* is a flag used for debugging messages.
+
+   *daemon* will flag the thread as daemonic.
+
    If the subclass overrides the constructor, it must make sure to invoke the base
    class constructor (``Thread.__init__()``) before doing anything else to the
    thread.
Index: Lib/threading.py
===================================================================
--- Lib/threading.py	(revision 73468)
+++ Lib/threading.py	(working copy)
@@ -407,7 +407,7 @@
     #XXX __exc_clear = _sys.exc_clear
 
     def __init__(self, group=None, target=None, name=None,
-                 args=(), kwargs=None, verbose=None):
+                 args=(), kwargs=None, verbose=None, daemon=False):
         assert group is None, "group argument must be None for now"
         _Verbose.__init__(self, verbose)
         if kwargs is None:
@@ -416,7 +416,7 @@
         self._name = str(name or _newname())
         self._args = args
         self._kwargs = kwargs
-        self._daemonic = self._set_daemon()
+        self._daemonic = daemon
         self._ident = None
         self._started = Event()
         self._stopped = False
@@ -426,10 +426,6 @@
         # sys.exc_info since it can be changed between instances
         self._stderr = _sys.stderr
 
-    def _set_daemon(self):
-        # Overridden in _MainThread and _DummyThread
-        return current_thread().daemon
-
     def __repr__(self):
         assert self._initialized, "Thread.__init__() was not called"
         status = "initial"
@@ -721,7 +717,7 @@
 class _MainThread(Thread):
 
     def __init__(self):
-        Thread.__init__(self, name="MainThread")
+        Thread.__init__(self, name="MainThread", daemon=False)
         self._started.set()
         self._set_ident()
         with _active_limbo_lock:
@@ -761,7 +757,7 @@
 class _DummyThread(Thread):
 
     def __init__(self):
-        Thread.__init__(self, name=_newname("Dummy-%d"))
+        Thread.__init__(self, name=_newname("Dummy-%d"), daemon=True)
 
         # Thread.__block consumes an OS-level locking primitive, which
         # can never be used by a _DummyThread.  Since a _DummyThread
Index: Lib/test/test_threading.py
===================================================================
--- Lib/test/test_threading.py	(revision 73468)
+++ Lib/test/test_threading.py	(working copy)
@@ -350,7 +350,15 @@
         e.isSet()
         threading.activeCount()
 
+    def test_deamon_param(self):
+        t = threading.Thread()
+        self.assertFalse(t.daemon)
+        t = threading.Thread(daemon=False)
+        self.assertFalse(t.daemon)
+        t = threading.Thread(daemon=True)
+        self.assertTrue(t.daemon)
 
+
 class ThreadJoinOnShutdown(unittest.TestCase):
 
     def _run_and_join(self, script):