diff --git a/boltconn/src/cli/mod.rs b/boltconn/src/cli/mod.rs
index 4aed2ae..afcf6b0 100644
--- a/boltconn/src/cli/mod.rs
+++ b/boltconn/src/cli/mod.rs
@@ -385,6 +385,7 @@ pub(crate) async fn controller_main(args: ProgramArgs) -> ! {
             DnsOptions::Lookup { domain_name } => requester.real_lookup(domain_name).await,
             DnsOptions::Mapping { fake_ip } => requester.fake_ip_to_real(fake_ip).await,
         },
+        #[cfg(feature = "internal-test")]
         SubCommand::MasterConn(opt) => match opt {
             MasterConnOptions::Wg => requester.master_conn_stats().await,
         },
diff --git a/boltconn/src/proxy/tun_udp_inbound.rs b/boltconn/src/proxy/tun_udp_inbound.rs
index d185496..adc03c4 100644
--- a/boltconn/src/proxy/tun_udp_inbound.rs
+++ b/boltconn/src/proxy/tun_udp_inbound.rs
@@ -109,7 +109,7 @@ impl TunUdpInbound {
                 // hijack dns
                 if let Ok(answer) = self.dns.respond_to_query(payload.as_ref()) {
                     let raw_data = create_raw_udp_pkt(answer.as_ref(), dst, src);
-                    if let Err(e) = self.tun_tx.send_async(raw_data.freeze()).await {
+                    if self.tun_tx.send_async(raw_data.freeze()).await.is_err() {
                         tracing::error!("TUN back tx closed");
                     }
                 }