--- tinysid-0.94-a/soundcard.c	2006-05-25 14:05:11.000000000 +0200
+++ tinysid-0.94-b/soundcard.c	2026-05-20 11:18:02.553896063 +0200
@@ -3,6 +3,7 @@
 #include <sys/ioctl.h>
 #include <pthread.h>
 #include <stdio.h>
+#include <unistd.h>
 
 #include "defines.h"