diff -r 2dde5a7439fd Doc/library/threading.rst
--- a/Doc/library/threading.rst	Thu Aug 30 14:56:13 2012 +0000
+++ b/Doc/library/threading.rst	Fri Aug 31 05:20:24 2012 -0700
@@ -202,6 +202,10 @@
 
    .. versionadded:: 2.5
 
+.. exception:: ThreadError
+
+    Raised when lock object cannot be acquired or released.
+
 Detailed interfaces for the objects are documented below.
 
 The design of this module is loosely based on Java's threading model. However,
@@ -387,7 +391,7 @@
 then the :meth:`acquire` call resets it to locked and returns.  The
 :meth:`release` method should only be called in the locked state; it changes the
 state to unlocked and returns immediately. If an attempt is made to release an
-unlocked lock, a :exc:`RuntimeError` will be raised.
+unlocked lock, a :exc:`ThreadError` will be raised.
 
 When more than one thread is blocked in :meth:`acquire` waiting for the state to
 turn to unlocked, only one thread proceeds when a :meth:`release` call resets