diff --git a/rott/rt_sound.c b/rott/rt_sound.c
index 1e55718..395a927 100644
--- a/rott/rt_sound.c
+++ b/rott/rt_sound.c
@@ -33,10 +33,6 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #include <stdio.h>
 #include <stdlib.h>
 
-#ifndef _MSC_VER
-#include <unistd.h>
-#endif
-
 #include "rt_cfg.h"
 #include "isr.h"
 #include "develop.h"