diff --git a/cmd/gluetun/main.go b/cmd/gluetun/main.go
index b23fbcd0..858b6845 100644
--- a/cmd/gluetun/main.go
+++ b/cmd/gluetun/main.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 	nativeos "os"
 	"os/signal"
+	"strconv"
 	"strings"
 	"syscall"
 	"time"
@@ -328,7 +329,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 		unboundLooper, updaterLooper, publicIPLooper, routingConf, logger, httpClient,
 		allSettings.VersionInformation, allSettings.OpenVPN.Provider.PortForwarding.Enabled, openvpnLooper.PortForward,
 	)
-	controlServerAddress := fmt.Sprintf("0.0.0.0:%d", allSettings.ControlServer.Port)
+	controlServerAddress := ":" + strconv.Itoa(int(allSettings.ControlServer.Port))
 	controlServerLogging := allSettings.ControlServer.Log
 	httpServer := server.New(controlServerAddress, controlServerLogging,
 		logger.NewChild(logging.Settings{Prefix: "http server: "}),
diff --git a/internal/shadowsocks/loop.go b/internal/shadowsocks/loop.go
index bfc8b3c0..cb0acb0b 100644
--- a/internal/shadowsocks/loop.go
+++ b/internal/shadowsocks/loop.go
@@ -3,7 +3,7 @@ package shadowsocks
 
 import (
 	"context"
-	"fmt"
+	"strconv"
 	"sync"
 	"time"
 
@@ -97,7 +97,7 @@ func (l *looper) Run(ctx context.Context, done chan<- struct{}) {
 
 		waitError := make(chan error)
 		go func() {
-			waitError <- server.Listen(shadowsocksCtx, fmt.Sprintf("0.0.0.0:%d", settings.Port))
+			waitError <- server.Listen(shadowsocksCtx, ":"+strconv.Itoa(int(settings.Port)))
 		}()
 		if err != nil {
 			crashed = true