diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
index 1813eeb..e59957b 100644
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -495,7 +495,10 @@ The :mod:`multiprocessing` package mostly replicates the API of the
 
       If the optional argument *timeout* is ``None`` (the default), the method
       blocks until the process whose :meth:`join` method is called terminates.
       If *timeout* is a positive number, it blocks at most *timeout* seconds.
+      Note that the method returns ``None`` if its process terminates or if the 
+      method times out. Check the process's *exitcode* to determine if it 
+      terminated.
 
       A process can be joined many times.