Index: Doc/library/multiprocessing.rst
===================================================================
--- Doc/library/multiprocessing.rst	(revision 78279)
+++ Doc/library/multiprocessing.rst	(working copy)
@@ -485,6 +485,9 @@
    the :mod:`multiprocessing` namespace so you need to import them from
    :mod:`Queue`.
 
+.. warning::
+   :class:`Queue` does not guarantee FIFO behavior under all circumstances.
+   See :issue:`4999` for additional information.
 
 .. warning::