diff --git a/include/stddef.h b/include/stddef.h
index 06fbd9bd..694d5037 100644
--- a/include/stddef.h
+++ b/include/stddef.h
@@ -8,8 +8,6 @@ typedef __PTRDIFF_TYPE__ ptrdiff_t;
 typedef __PTRDIFF_TYPE__ intptr_t;
 typedef __SIZE_TYPE__ uintptr_t;
 
-typedef union { long long __ll; long double __ld; } max_align_t;
-
 #ifndef __int8_t_defined
 #define __int8_t_defined
 typedef signed char int8_t;