--- a/Buf.h.org
+++ b/Buf.h
@@ -93,6 +93,7 @@
 #define BUF_H
 
 #include "utils.h"
+#include <sys/types.h>
 
 #define	BUFFER_MAX_CHUNK	0x100000
 #define	BUFFER_MAX_LEN		0xa00000