diff --git a/defines.h b/defines.h
index 1b328a4..dce2d05 100644
--- a/defines.h
+++ b/defines.h
@@ -2,9 +2,9 @@
 #ifndef __DEFINES_H__
 #define __DEFINES_H__
 
-#if __unix__
+#if __unix__ || (defined(__APPLE__) && defined(__MACH__))
 # define UNIX 1
-# if __NetBSD__
+# if __NetBSD__ || (defined(__APPLE__) && defined(__MACH__))
 #  define BSD 1
 #  define POSIX 1
 # elif __linux__
diff --git a/main.c b/main.c
index 413dad1..dc3344f 100644
--- a/main.c
+++ b/main.c
@@ -69,6 +69,7 @@
 #include "defines.h"	/* OS specific customization */
 #if UNIX
 # include <signal.h>
+# include <unistd.h>
 #endif
 
 #include "basic.h"