diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index 7a8707632a81..9d335aa58907 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -288,6 +288,15 @@ static bool nft_flow_offload_skip(struct sk_buff *skb, int family)
 	return false;
 }
 
+static void flow_offload_ct_tcp(struct nf_conn *ct)
+{
+	/* conntrack will not see all packets, disable tcp window validation. */
+	spin_lock_bh(&ct->lock);
+	ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
+	ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
+	spin_unlock_bh(&ct->lock);
+}
+
 static void nft_flow_offload_eval(const struct nft_expr *expr,
 				  struct nft_regs *regs,
 				  const struct nft_pktinfo *pkt)
@@ -355,11 +364,8 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
 		goto err_flow_alloc;
 
 	flow_offload_route_init(flow, &route);
-
-	if (tcph) {
-		ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
-		ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
-	}
+	if (tcph)
+		flow_offload_ct_tcp(ct);
 
 	ret = flow_offload_add(flowtable, flow);
 	if (ret < 0)