--- vorbisgain-0.37/misc.c	2004-01-03 16:17:28.000000000 -0500
+++ vorbisgain-0.37-patched/misc.c	2025-01-07 20:35:13.056221211 -0500
@@ -23,6 +23,7 @@
 #else /* WIN32 */
 #include <errno.h>
 #include <ctype.h>
+#include <unistd.h>
 
 #ifndef DISABLE_WINSIZE