diff --git a/pkg/proxy/util/utils.go b/pkg/proxy/util/utils.go
index 59d85a54d62..b55efd8eea2 100644
--- a/pkg/proxy/util/utils.go
+++ b/pkg/proxy/util/utils.go
@@ -19,6 +19,7 @@ package util
 import (
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 	"time"
 
@@ -169,10 +170,7 @@ func AppendPortIfNeeded(addr string, port int32) string {
 	}
 
 	// Append port to address.
-	if ip.To4() != nil {
-		return fmt.Sprintf("%s:%d", addr, port)
-	}
-	return fmt.Sprintf("[%s]:%d", addr, port)
+	return net.JoinHostPort(addr, strconv.Itoa(int(port)))
 }
 
 // EnsureSysctl sets a kernel sysctl to a given numeric value.