diff --git a/libcxx/include/cstddef b/libcxx/include/cstddef
index 8264a8b29cae..11d07a2ec292 100644
--- a/libcxx/include/cstddef
+++ b/libcxx/include/cstddef
@@ -34,10 +34,6 @@ Types:
 */
 
 #include <__config>
-#define __need_NULL
-#define __need_ptrdiff_t
-#define __need_size_t
-#include <stddef.h>
 #include <stddef.h>
 
 #pragma GCC system_header