diff --git a/.gitignore b/.gitignore
index ea8c4bf..2d5df85 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /target
+.direnv
diff --git a/src/tcp_to_udp.rs b/src/tcp_to_udp.rs
index b09cae8..1fa4c11 100644
--- a/src/tcp_to_udp.rs
+++ b/src/tcp_to_udp.rs
@@ -1,4 +1,5 @@
 use std::{
+    env,
     io::{Read, Write},
     net::{TcpListener, UdpSocket},
     thread,
@@ -15,7 +16,11 @@ impl Ports {
             let mut tcp = tcp_listener.accept().unwrap().0;
             thread::spawn(move || {
                 let udp = UdpSocket::bind(("127.0.0.1", 0)).unwrap();
-                udp.connect(("127.0.0.1", self.udp)).unwrap();
+                udp.connect((
+                    env::var("TCPUDP_OTHER").unwrap_or("127.0.0.1".to_owned()),
+                    self.udp,
+                ))
+                .unwrap();
                 {
                     let (mut tcp, udp) = (tcp.try_clone().unwrap(), udp.try_clone().unwrap());
                     thread::spawn(move || {
diff --git a/src/udp_to_tcp.rs b/src/udp_to_tcp.rs
index 2270380..0a55e1f 100644
--- a/src/udp_to_tcp.rs
+++ b/src/udp_to_tcp.rs
@@ -1,5 +1,6 @@
 use std::{
     collections::HashMap,
+    env,
     io::{Read, Write},
     net::{Shutdown, SocketAddr, TcpStream, UdpSocket},
     thread,
@@ -18,7 +19,11 @@ impl Ports {
             let (len, addr) = udp_listener.recv_from(&mut buf).unwrap();
             let mut tcp_socket = map.get(&addr);
             if tcp_socket.is_none() {
-                let tcp = TcpStream::connect(("127.0.0.1", self.tcp)).unwrap();
+                let tcp = TcpStream::connect((
+                    env::var("TCPUDP_OTHER").unwrap_or("127.0.0.1".to_owned()),
+                    self.tcp,
+                ))
+                .unwrap();
                 {
                     let (mut tcp, addr, udp) = (
                         tcp.try_clone().unwrap(),