Index: src/unistd_wrapper.h
==================================================================
--- src/unistd_wrapper.h
+++ src/unistd_wrapper.h
@@ -15,14 +15,16 @@
 
 #include "config.h"
 
 #include <stdlib.h>	/* Make sure we have any libc include */
 
-#ifdef HAVE_UNISTD_H
+#import "platform.h"
+
+#if defined(HAVE_UNISTD_H) && (!defined(OF_MORPHOS) || defined(OF_IXEMUL))
 # ifdef __GLIBC__
 #  undef __USE_XOPEN	/* Needed to avoid old glibc using __block */
 # endif
 # include <unistd.h>
 # ifdef __GLIBC__
 #  define __USE_XOPEN 1
 # endif
 #endif