diff --git a/worker/src/build.rs b/worker/src/build.rs
index d6cc710..e5eee62 100644
--- a/worker/src/build.rs
+++ b/worker/src/build.rs
@@ -2,32 +2,29 @@ use crate::{get_memory_bytes, Args};
 use anyhow::Context;
 use chrono::Local;
 use common::{JobOk, WorkerJobUpdateRequest, WorkerPollRequest, WorkerPollResponse};
-use futures_util::{stream::SplitSink, SinkExt, StreamExt};
+use futures_util::{SinkExt, StreamExt};
 use log::{error, info, warn};
 use std::{
     path::Path,
     process::{Output, Stdio},
-    sync::Arc,
     time::{Duration, Instant},
 };
 use tokio::{
     fs,
     io::{AsyncBufReadExt, BufReader},
-    net::TcpStream,
     process::Command,
-    sync::Mutex,
+    sync::mpsc::{unbounded_channel, UnboundedSender},
     time::sleep,
 };
-use tokio_tungstenite::{connect_async, tungstenite::Message, MaybeTlsStream, WebSocketStream};
+use tokio_tungstenite::{connect_async, tungstenite::Message};
 
-type WsWriter = SplitSink<WebSocketStream<MaybeTlsStream<TcpStream>>, Message>;
 
 async fn get_output_logged(
     cmd: &str,
     args: &[&str],
     cwd: &Path,
     logs: &mut Vec<u8>,
-    write: Arc<Mutex<WsWriter>>,
+    tx: UnboundedSender<String>,
 ) -> anyhow::Result<Output> {
     let begin = Instant::now();
     let msg = format!(
@@ -53,14 +50,13 @@ async fn get_output_logged(
     let mut stdout_reader = BufReader::new(stdout).lines();
     let stderr = output.stderr.take().context("Failed to get stderr")?;
 
-    let wc = write.clone();
+    let txc = tx.clone();
 
     let stderr_task = tokio::spawn(async move {
         let mut res = vec![];
         let mut stderr_reader = BufReader::new(stderr).lines();
         while let Ok(Some(v)) = stderr_reader.next_line().await {
-            let mut lock = wc.lock().await;
-            let _ = lock.send(Message::Text(v.clone())).await;
+            let _ = txc.send(v.clone());
             res.push(v);
         }
 
@@ -69,8 +65,7 @@ async fn get_output_logged(
 
     let mut stdout_out = vec![];
     while let Ok(Some(v)) = stdout_reader.next_line().await {
-        let mut lock = write.lock().await;
-        lock.send(Message::Text(v.clone())).await?;
+        tx.send(v.clone())?;
         stdout_out.push(v);
     }
 
@@ -101,13 +96,13 @@ async fn run_logged_with_retry(
     args: &[&str],
     cwd: &Path,
     logs: &mut Vec<u8>,
-    write: Arc<Mutex<WsWriter>>,
+    tx: UnboundedSender<String>,
 ) -> anyhow::Result<bool> {
     for i in 0..5 {
         if i > 0 {
             info!("Attempt #{i} to run `{cmd} {}`", args.join(" "));
         }
-        match get_output_logged(cmd, args, cwd, logs, write.clone()).await {
+        match get_output_logged(cmd, args, cwd, logs, tx.clone()).await {
             Ok(output) => {
                 if output.status.success() {
                     return Ok(true);
@@ -134,7 +129,7 @@ async fn build(
     job: &WorkerPollResponse,
     tree_path: &Path,
     args: &Args,
-    write: Arc<Mutex<WsWriter>>,
+    tx: UnboundedSender<String>,
 ) -> anyhow::Result<WorkerJobUpdateRequest> {
     let begin = Instant::now();
     let mut successful_packages = vec![];
@@ -148,14 +143,7 @@ async fn build(
 
     // clear output directory
     if output_path.exists() {
-        get_output_logged(
-            "rm",
-            &["-rf", "debs"],
-            &output_path,
-            &mut logs,
-            write.clone(),
-        )
-        .await?;
+        get_output_logged("rm", &["-rf", "debs"], &output_path, &mut logs, tx.clone()).await?;
     }
 
     // switch to git ref
@@ -168,7 +156,7 @@ async fn build(
         ],
         tree_path,
         &mut logs,
-        write.clone(),
+        tx.clone(),
     )
     .await?;
 
@@ -182,7 +170,7 @@ async fn build(
             &["checkout", "-b", &job.git_branch],
             tree_path,
             &mut logs,
-            write.clone(),
+            tx.clone(),
         )
         .await?;
         // checkout to branch
@@ -191,7 +179,7 @@ async fn build(
             &["checkout", &job.git_branch],
             tree_path,
             &mut logs,
-            write.clone(),
+            tx.clone(),
         )
         .await?;
 
@@ -202,7 +190,7 @@ async fn build(
             &["reset", &job.git_sha, "--hard"],
             tree_path,
             &mut logs,
-            write.clone(),
+            tx.clone(),
         )
         .await?;
 
@@ -213,21 +201,16 @@ async fn build(
                 &["update-os"],
                 &args.ciel_path,
                 &mut logs,
-                write.clone(),
+                tx.clone(),
             )
             .await?;
 
             // build packages
             let mut ciel_args = vec!["build", "-i", &args.ciel_instance];
             ciel_args.extend(job.packages.split(','));
-            let output = get_output_logged(
-                "ciel",
-                &ciel_args,
-                &args.ciel_path,
-                &mut logs,
-                write.clone(),
-            )
-            .await?;
+            let output =
+                get_output_logged("ciel", &ciel_args, &args.ciel_path, &mut logs, tx.clone())
+                    .await?;
 
             build_success = output.status.success();
 
@@ -297,7 +280,7 @@ async fn build(
                         &args,
                         &output_path,
                         &mut logs,
-                        write.clone(),
+                        tx.clone(),
                     )
                     .await?;
                 }
@@ -330,7 +313,7 @@ async fn build(
             ],
             &tree_path,
             &mut scp_log,
-            write,
+            tx,
         )
         .await?
         {
@@ -373,8 +356,10 @@ async fn build(
 async fn build_worker_inner(args: &Args) -> anyhow::Result<()> {
     let ws = &args.websocket;
     let (ws_stream, _) = connect_async(ws).await?;
-    let (write, _) = ws_stream.split();
-    let write = Arc::new(Mutex::new(write));
+    let (mut write, _) = ws_stream.split();
+
+    let (tx, mut rx): (UnboundedSender<String>, _) = unbounded_channel();
+
     let mut tree_path = args.ciel_path.clone();
     tree_path.push("TREE");
 
@@ -393,6 +378,12 @@ async fn build_worker_inner(args: &Args) -> anyhow::Result<()> {
         logical_cores: num_cpus::get() as i32,
     };
 
+    tokio::spawn(async move {
+        if let Some(v) = rx.recv().await {
+            let _ = write.send(Message::Text(v)).await;
+        }
+    });
+
     loop {
         if let Some(job) = client
             .post(format!("{}/api/worker/poll", args.server))
@@ -404,7 +395,7 @@ async fn build_worker_inner(args: &Args) -> anyhow::Result<()> {
         {
             info!("Processing job {:?}", job);
 
-            match build(&job, &tree_path, args, write.clone()).await {
+            match build(&job, &tree_path, args, tx.clone()).await {
                 Ok(result) => {
                     // post result
                     info!("Finished to run job {:?} with result {:?}", job, result);