diff --git a/sysdeps/mach/hurd/start.c b/sysdeps/mach/hurd/start.c
index 10d6e72228..9a70e0ddd4 100644
--- a/sysdeps/mach/hurd/start.c
+++ b/sysdeps/mach/hurd/start.c
@@ -24,6 +24,7 @@ Cambridge, MA 02139, USA.  */
 #include <hurd/exec.h>
 #include <sysdep.h>
 #include <hurd/threadvar.h>
+#include <unistd.h>
 #include "set-hooks.h"
 #include "hurdmalloc.h"		/* XXX */