diff -Nurd vorbisgain-0.37.orig/configure vorbisgain-0.37/configure
--- vorbisgain-0.37.orig/configure	2005-07-14 18:50:59.000000000 -0400
+++ vorbisgain-0.37/configure	2023-11-16 08:41:34.000000000 -0500
@@ -3894,6 +3894,7 @@
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
 #include <ctype.h>
+#include <stdlib.h>
 #if ((' ' & 0x0FF) == 0x020)
 # define ISLOWER(c) ('a' <= (c) && (c) <= 'z')
 # define TOUPPER(c) (ISLOWER(c) ? 'A' + ((c) - 'a') : (c))
diff -Nurd vorbisgain-0.37.orig/misc.c vorbisgain-0.37/misc.c
--- vorbisgain-0.37.orig/misc.c	2004-01-03 16:17:28.000000000 -0500
+++ vorbisgain-0.37/misc.c	2023-11-16 08:43:41.000000000 -0500
@@ -14,6 +14,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
 #include <vorbis/codec.h>
 #include "i18n.h"
 #include "misc.h"