diff --git a/Cargo.lock b/Cargo.lock
index d3b5f860..b20314a5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1733,6 +1733,7 @@ dependencies = [
  "native-tls",
  "nix",
  "once_cell",
+ "parking_lot",
  "pin-project",
  "qrcode",
  "rand",
diff --git a/crates/shadowsocks-service/Cargo.toml b/crates/shadowsocks-service/Cargo.toml
index fd7c590d..a75ce714 100644
--- a/crates/shadowsocks-service/Cargo.toml
+++ b/crates/shadowsocks-service/Cargo.toml
@@ -56,7 +56,7 @@ local-tunnel = ["local"]
 # Enable socks4 protocol for sslocal
 local-socks4 = ["local"]
 # Enable Tun interface protocol for sslocal
-local-tun = ["local", "etherparse", "tun", "rand", "smoltcp"]
+local-tun = ["local", "etherparse", "tun", "rand", "smoltcp", "parking_lot"]
 
 # Enable Stream Cipher Protocol
 # WARN: Stream Cipher Protocol is proved to be insecure
@@ -90,6 +90,7 @@ bytes = "1.0"
 byte_string = "1.0"
 byteorder = "1.3"
 rand = { version = "0.8", optional = true }
+parking_lot = { version = "0.11", optional = true }
 
 futures = "0.3"
 tokio = { version = "1.5", features = ["io-util", "macros", "net", "parking_lot", "rt", "sync", "time"] }
diff --git a/crates/shadowsocks-service/src/local/tun/tcp.rs b/crates/shadowsocks-service/src/local/tun/tcp.rs
index c17a0af6..65f9becd 100644
--- a/crates/shadowsocks-service/src/local/tun/tcp.rs
+++ b/crates/shadowsocks-service/src/local/tun/tcp.rs
@@ -3,12 +3,13 @@ use std::{
     io::{self, ErrorKind},
     net::{IpAddr, SocketAddr},
     pin::Pin,
-    sync::{Arc, Mutex as StdMutex},
+    sync::Arc,
     task::{Context, Poll},
     time::Duration as StdDuration,
 };
 
 use log::{error, trace};
+use parking_lot::Mutex as ParkingMutex;
 use shadowsocks::relay::socks5::Address;
 use smoltcp::{
     iface::{Interface, InterfaceBuilder, Routes, SocketHandle},
@@ -44,7 +45,7 @@ impl TcpSocketManager {
     }
 }
 
-type SharedTcpSocketManager = Arc<StdMutex<TcpSocketManager>>;
+type SharedTcpSocketManager = Arc<ParkingMutex<TcpSocketManager>>;
 
 struct TcpConnection {
     socket_handle: SocketHandle,
@@ -53,7 +54,7 @@ struct TcpConnection {
 
 impl Drop for TcpConnection {
     fn drop(&mut self) {
-        let mut manager = self.manager.lock().unwrap();
+        let mut manager = self.manager.lock();
         let socket = manager.iface.get_socket::<TcpSocket>(self.socket_handle);
         socket.close();
     }
@@ -62,7 +63,7 @@ impl Drop for TcpConnection {
 impl TcpConnection {
     fn new(socket: TcpSocket<'static>, manager: SharedTcpSocketManager) -> TcpConnection {
         let socket_handle = {
-            let mut manager = manager.lock().unwrap();
+            let mut manager = manager.lock();
             manager.iface.add_socket(socket)
         };
 
@@ -72,7 +73,7 @@ impl TcpConnection {
 
 impl AsyncRead for TcpConnection {
     fn poll_read(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &mut ReadBuf<'_>) -> Poll<io::Result<()>> {
-        let mut manager = self.manager.lock().unwrap();
+        let mut manager = self.manager.lock();
         {
             let socket = manager.iface.get_socket::<TcpSocket>(self.socket_handle);
             if !socket.is_open() {
@@ -99,7 +100,7 @@ impl AsyncRead for TcpConnection {
 
 impl AsyncWrite for TcpConnection {
     fn poll_write(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8]) -> Poll<io::Result<usize>> {
-        let mut manager = self.manager.lock().unwrap();
+        let mut manager = self.manager.lock();
         let n = {
             let socket = manager.iface.get_socket::<TcpSocket>(self.socket_handle);
             if !socket.is_open() {
@@ -125,7 +126,7 @@ impl AsyncWrite for TcpConnection {
     }
 
     fn poll_shutdown(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
-        let mut manager = self.manager.lock().unwrap();
+        let mut manager = self.manager.lock();
         {
             let socket = manager.iface.get_socket::<TcpSocket>(self.socket_handle);
             // close the transmission half.
@@ -186,7 +187,7 @@ impl TcpTun {
             .finalize();
 
         let manager_notify = Arc::new(Notify::new());
-        let manager = Arc::new(StdMutex::new(TcpSocketManager {
+        let manager = Arc::new(ParkingMutex::new(TcpSocketManager {
             iface,
             manager_notify: manager_notify.clone(),
         }));
@@ -197,7 +198,7 @@ impl TcpTun {
             tokio::spawn(async move {
                 loop {
                     let next_duration = {
-                        let mut manager = manager.lock().unwrap();
+                        let mut manager = manager.lock();
 
                         if let Err(err) = manager.iface.poll(Instant::now()) {
                             error!("virtual device error: {}", err);