diff --git a/Doc/library/select.rst b/Doc/library/select.rst
index 4fae87e..4bf1a9f 100644
--- a/Doc/library/select.rst
+++ b/Doc/library/select.rst
@@ -377,9 +377,13 @@
 
    Modifies an already registered fd. This has the same effect as
    ``register(fd, eventmask)``.  Attempting to modify a file descriptor
-   that was never registered causes an :exc:`IOError` exception with errno
+   that was never registered causes an :exc:`OSError` exception with errno
    :const:`ENOENT` to be raised.
 
+   .. deprecated:: 3.3
+
+      Instead of :exc:`IOError` the :exc:`OSError` exception is used now.
+
 
 .. method:: poll.unregister(fd)