diff --git a/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c b/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
index 8c67505865a4691aea80133ee0f1964d4140c9f8..a7a80f4b722a9d7dc2d5efa7d5b89fc93bedcb33 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/tunnel_conf.c
@@ -162,8 +162,7 @@ void nfp_tunnel_keep_alive(struct nfp_app *app, struct sk_buff *skb)
 	}
 
 	pay_len = nfp_flower_cmsg_get_data_len(skb);
-	if (pay_len != sizeof(struct nfp_tun_active_tuns) +
-	    sizeof(struct route_ip_info) * count) {
+	if (pay_len != struct_size(payload, tun_info, count)) {
 		nfp_flower_cmsg_warn(app, "Corruption in tunnel keep-alive message.\n");
 		return;
 	}