diff --git a/cmd/clef/main.go b/cmd/clef/main.go
index 14f09dc1a..a8b0bf816 100644
--- a/cmd/clef/main.go
+++ b/cmd/clef/main.go
@@ -27,6 +27,7 @@ import (
 	"fmt"
 	"io"
 	"math/big"
+	"net"
 	"os"
 	"os/signal"
 	"path/filepath"
@@ -743,7 +744,7 @@ func signer(c *cli.Context) error {
 		port := c.Int(rpcPortFlag.Name)
 
 		// start http server
-		httpEndpoint := fmt.Sprintf("%s:%d", c.String(utils.HTTPListenAddrFlag.Name), port)
+		httpEndpoint := net.JoinHostPort(c.String(utils.HTTPListenAddrFlag.Name), fmt.Sprintf("%d", port))
 		httpServer, addr, err := node.StartHTTPEndpoint(httpEndpoint, rpc.DefaultHTTPTimeouts, handler)
 		if err != nil {
 			utils.Fatalf("Could not start RPC api: %v", err)
diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 7bb47f128..6f0e57025 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -26,6 +26,7 @@ import (
 	"fmt"
 	"math"
 	"math/big"
+	"net"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -2014,7 +2015,7 @@ func SetupMetrics(ctx *cli.Context) {
 		}
 
 		if ctx.IsSet(MetricsHTTPFlag.Name) {
-			address := fmt.Sprintf("%s:%d", ctx.String(MetricsHTTPFlag.Name), ctx.Int(MetricsPortFlag.Name))
+			address := net.JoinHostPort(ctx.String(MetricsHTTPFlag.Name), fmt.Sprintf("%d", ctx.Int(MetricsPortFlag.Name)))
 			log.Info("Enabling stand-alone metrics HTTP endpoint", "address", address)
 			exp.Setup(address)
 		} else if ctx.IsSet(MetricsPortFlag.Name) {
diff --git a/internal/debug/flags.go b/internal/debug/flags.go
index d425a17db..52a634245 100644
--- a/internal/debug/flags.go
+++ b/internal/debug/flags.go
@@ -19,6 +19,7 @@ package debug
 import (
 	"fmt"
 	"io"
+	"net"
 	"net/http"
 	_ "net/http/pprof"
 	"os"
@@ -308,7 +309,7 @@ func Setup(ctx *cli.Context) error {
 
 		port := ctx.Int(pprofPortFlag.Name)
 
-		address := fmt.Sprintf("%s:%d", listenHost, port)
+		address := net.JoinHostPort(listenHost, fmt.Sprintf("%d", port))
 		// This context value ("metrics.addr") represents the utils.MetricsHTTPFlag.Name.
 		// It cannot be imported because it will cause a cyclical dependency.
 		StartPProf(address, !ctx.IsSet("metrics.addr"))
diff --git a/node/config.go b/node/config.go
index 37c1e4882..949db887e 100644
--- a/node/config.go
+++ b/node/config.go
@@ -19,6 +19,7 @@ package node
 import (
 	"crypto/ecdsa"
 	"fmt"
+	"net"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -263,7 +264,7 @@ func (c *Config) HTTPEndpoint() string {
 	if c.HTTPHost == "" {
 		return ""
 	}
-	return fmt.Sprintf("%s:%d", c.HTTPHost, c.HTTPPort)
+	return net.JoinHostPort(c.HTTPHost, fmt.Sprintf("%d", c.HTTPPort))
 }
 
 // DefaultHTTPEndpoint returns the HTTP endpoint used by default.
@@ -278,7 +279,7 @@ func (c *Config) WSEndpoint() string {
 	if c.WSHost == "" {
 		return ""
 	}
-	return fmt.Sprintf("%s:%d", c.WSHost, c.WSPort)
+	return net.JoinHostPort(c.WSHost, fmt.Sprintf("%d", c.WSPort))
 }
 
 // DefaultWSEndpoint returns the websocket endpoint used by default.
diff --git a/node/rpcstack.go b/node/rpcstack.go
index e91585a2b..b33c23805 100644
--- a/node/rpcstack.go
+++ b/node/rpcstack.go
@@ -112,7 +112,7 @@ func (h *httpServer) setListenAddr(host string, port int) error {
 	}
 
 	h.host, h.port = host, port
-	h.endpoint = fmt.Sprintf("%s:%d", host, port)
+	h.endpoint = net.JoinHostPort(host, fmt.Sprintf("%d", port))
 	return nil
 }