diff --git a/internal/ingress/controller/endpoints.go b/internal/ingress/controller/endpoints.go
index 368ba2b1d3..3f558638df 100644
--- a/internal/ingress/controller/endpoints.go
+++ b/internal/ingress/controller/endpoints.go
@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"net"
 	"reflect"
+	"strconv"
 
 	"github.com/golang/glog"
 
@@ -100,7 +101,7 @@ func getEndpoints(s *corev1.Service, port *corev1.ServicePort, proto corev1.Prot
 			}
 
 			for _, epAddress := range ss.Addresses {
-				ep := fmt.Sprintf("%v:%v", epAddress.IP, targetPort)
+				ep := net.JoinHostPort(epAddress.IP, strconv.Itoa(int(targetPort)))
 				if _, exists := processedUpstreamServers[ep]; exists {
 					continue
 				}
diff --git a/test/e2e/settings/proxy_protocol.go b/test/e2e/settings/proxy_protocol.go
index 95e3ebc928..acf10d7184 100644
--- a/test/e2e/settings/proxy_protocol.go
+++ b/test/e2e/settings/proxy_protocol.go
@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net"
+	"strconv"
 	"strings"
 
 	. "github.com/onsi/ginkgo"
@@ -66,7 +67,7 @@ var _ = framework.IngressNginxDescribe("Proxy Protocol", func() {
 		port, err := f.GetNginxPort("http")
 		Expect(err).NotTo(HaveOccurred())
 
-		conn, err := net.Dial("tcp", fmt.Sprintf("%v:%v", ip, port))
+		conn, err := net.Dial("tcp", net.JoinHostPort(ip, strconv.Itoa(port)))
 		Expect(err).NotTo(HaveOccurred())
 		defer conn.Close()