diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index db870783e..7c2aa3bc1 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -250,8 +250,10 @@
 #endif
 #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__)
 #define	__alloc_size(x)	__attribute__((__alloc_size__ x))
+#define	__alloc_size2(n, x)	__attribute__((__alloc_size__(n, x)))
 #else
 #define	__alloc_size(x)
+#define	__alloc_size2(n, x)
 #endif
 #if __GNUC_PREREQ__(4, 9) || __has_attribute(__alloc_align__)
 #define	__alloc_align(x)	__attribute__((__alloc_align__ x))