diff --git a/dumpling/export/config.go b/dumpling/export/config.go
index efd41bcd3082e..5c36557f6a4d1 100644
--- a/dumpling/export/config.go
+++ b/dumpling/export/config.go
@@ -8,6 +8,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"strconv"
 	"strings"
 	"text/template"
@@ -199,8 +200,9 @@ func (conf *Config) String() string {
 func (conf *Config) GetDSN(db string) string {
 	// maxAllowedPacket=0 can be used to automatically fetch the max_allowed_packet variable from server on every connection.
 	// https://github.com/go-sql-driver/mysql#maxallowedpacket
-	dsn := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?collation=utf8mb4_general_ci&readTimeout=%s&writeTimeout=30s&interpolateParams=true&maxAllowedPacket=0",
-		conf.User, conf.Password, conf.Host, conf.Port, db, conf.ReadTimeout)
+	hostPort := net.JoinHostPort(conf.Host, strconv.Itoa(conf.Port))
+	dsn := fmt.Sprintf("%s:%s@tcp(%s)/%s?collation=utf8mb4_general_ci&readTimeout=%s&writeTimeout=30s&interpolateParams=true&maxAllowedPacket=0",
+		conf.User, conf.Password, hostPort, db, conf.ReadTimeout)
 	if len(conf.Security.CAPath) > 0 {
 		dsn += "&tls=dumpling-tls-target"
 	}