diff --git a/src/core/ipv6/icmp6.c b/src/core/ipv6/icmp6.c
index 2302c8e6..08db3817 100644
--- a/src/core/ipv6/icmp6.c
+++ b/src/core/ipv6/icmp6.c
@@ -402,7 +402,7 @@ icmp6_send_response_with_addrs_and_netif(struct pbuf *p, u8_t code, u32_t data,
   icmp6hdr = (struct icmp6_hdr *)q->payload;
   icmp6hdr->type = type;
   icmp6hdr->code = code;
-  icmp6hdr->data = data;
+  icmp6hdr->data = lwip_htonl(data);
 
   /* copy fields from original packet */
   SMEMCPY((u8_t *)q->payload + sizeof(struct icmp6_hdr), (u8_t *)p->payload,