diff --git a/libc/kernel/uapi/linux/rpl.h b/libc/kernel/uapi/linux/rpl.h
index 3648bfc..4226297 100644
--- a/libc/kernel/uapi/linux/rpl.h
+++ b/libc/kernel/uapi/linux/rpl.h
@@ -34,8 +34,8 @@
 #error "Please fix <asm/byteorder.h>"
 #endif
   union {
-    struct in6_addr addr[0];
-    __u8 data[0];
+    __DECLARE_FLEX_ARRAY(struct in6_addr, addr);
+    __DECLARE_FLEX_ARRAY(__u8, data);
   } segments;
 } __attribute__((packed));
 #define rpl_segaddr segments.addr