--- Libc/Libc-997.1.1/include/vis.h
+++ Libc/Libc-391.4.2/include/vis.h
@@ -59,7 +59,11 @@
 #define	_VIS_H_
 
 #include <_types.h>
-#include <sys/_types/_size_t.h>
+
+#ifndef	_SIZE_T
+#define	_SIZE_T
+typedef	__darwin_size_t		size_t;
+#endif
 
 /*
  * to select alternate encoding format