diff --git a/src/platform/str9/type.h b/src/platform/str9/type.h
index 02c04def..85c7b3e8 100644
--- a/src/platform/str9/type.h
+++ b/src/platform/str9/type.h
@@ -1,17 +1,8 @@
 #ifndef __TYPE_H__
 #define __TYPE_H__
 
-#ifndef NULL
-#define NULL    ((void *)0)
-#endif
-
-#ifndef FALSE
-#define FALSE   (0)
-#endif
-
-#ifndef TRUE
-#define TRUE    (1)
-#endif
+#include <stdbool.h>
+enum { FALSE = 0, TRUE  = !FALSE };
 
 typedef unsigned char  BYTE;
 typedef unsigned short WORD;