Issue #4204: Fixed module build errors on FreeBSD 4.
diff --git a/Modules/_multiprocessing/multiprocessing.h b/Modules/_multiprocessing/multiprocessing.h
index 0b32790..2bfad87 100644
--- a/Modules/_multiprocessing/multiprocessing.h
+++ b/Modules/_multiprocessing/multiprocessing.h
@@ -20,7 +20,9 @@
# define SEM_VALUE_MAX LONG_MAX
#else
# include <fcntl.h> /* O_CREAT and O_EXCL */
+# include <netinet/in.h>
# include <sys/socket.h>
+# include <sys/uio.h>
# include <arpa/inet.h> /* htonl() and ntohl() */
# if HAVE_SEM_OPEN
# include <semaphore.h>