diff --git a/main.go b/main.go
index 10a41a6..50fb88b 100644
--- a/main.go
+++ b/main.go
@@ -5,11 +5,8 @@ import (
 	"bytes"
 	"encoding/binary"
 	"encoding/hex"
-	"os"
-)
-
-import (
 	"milter-experiment/logging"
+	"os"
 )
 
 var (
@@ -43,7 +40,7 @@ func handleMtaConnection(clientConnection *bufio.ReadWriter) {
 
 func main() {
 	logger = logging.NewLogger(os.Stdout, os.Stderr, logging.DEBUG)
-	err := runServer()
+	err := runServer("127.0.0.1:7777")
 	if err != nil {
 		logger.Errorf("Could not run server: %s\n", err.Error())
 		os.Exit(1)
diff --git a/socket.go b/socket.go
index 2d7566e..3986b8c 100644
--- a/socket.go
+++ b/socket.go
@@ -6,8 +6,8 @@ import (
 	"net"
 )
 
-func runServer() error {
-	serverSocket, err := net.Listen("tcp", "127.0.0.1:7777")
+func runServer(listenAddr string) error {
+	serverSocket, err := net.Listen("tcp", listenAddr)
 	if err != nil {
 		myError := fmt.Errorf("could not create listening socket: %s", err.Error())
 		return myError