diff --git a/go.mod b/go.mod
index 2319da9..38c9ffb 100644
--- a/go.mod
+++ b/go.mod
@@ -8,3 +8,5 @@ require (
 )
 
 require golang.org/x/net v0.38.0
+
+replace github.com/armon/go-socks5 => github.com/serjs/go-socks5 v0.0.0-20250923183437-3920b97ee0d2
diff --git a/go.sum b/go.sum
index 90cec29..a10cf3c 100644
--- a/go.sum
+++ b/go.sum
@@ -1,6 +1,8 @@
-github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
-github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5/go.mod h1:wHh0iHkYZB8zMSxRWpUBQtwG5a7fFgvEO+odwuTv2gs=
 github.com/caarlos0/env/v6 v6.10.1 h1:t1mPSxNpei6M5yAeu1qtRdPAK29Nbcf/n3G7x+b3/II=
 github.com/caarlos0/env/v6 v6.10.1/go.mod h1:hvp/ryKXKipEkcuYjs9mI4bBCg+UI0Yhgm5Zu0ddvwc=
+github.com/serjs/go-socks5 v0.0.0-20250923182028-346d18438915 h1:fgMfP6jRY4Dq+CFFNpC0hu/tyJj35tlcJphNkutvO98=
+github.com/serjs/go-socks5 v0.0.0-20250923182028-346d18438915/go.mod h1:N2PhU16m3olAb71DduLys4mYR3oQboD4uLJmSXCSuMA=
+github.com/serjs/go-socks5 v0.0.0-20250923183437-3920b97ee0d2 h1:dIXY/Lrkd1rGXcN60Fc0M2x0p5/C2XcbBbtPCvVvAa4=
+github.com/serjs/go-socks5 v0.0.0-20250923183437-3920b97ee0d2/go.mod h1:N2PhU16m3olAb71DduLys4mYR3oQboD4uLJmSXCSuMA=
 golang.org/x/net v0.38.0 h1:vRMAPTMaeGqVhG5QyLJHqNDwecKTomGeqbnfZyKlBI8=
 golang.org/x/net v0.38.0/go.mod h1:ivrbrMbzFq5J41QOQh0siUuly180yBYtLp+CKbEaFx8=
diff --git a/server.go b/server.go
index 96c9c84..9e3568b 100644
--- a/server.go
+++ b/server.go
@@ -2,8 +2,8 @@ package main
 
 import (
 	"log"
+	"net"
 	"os"
-
 	"github.com/armon/go-socks5"
 	"github.com/caarlos0/env/v6"
 )
@@ -45,7 +45,7 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	{{/*
+
 	// Set IP whitelist
 	if len(cfg.AllowedIPs) > 0 {
 		whitelist := make([]net.IP, len(cfg.AllowedIPs))
@@ -54,7 +54,6 @@ func main() {
 		}
 		server.SetIPWhitelist(whitelist)
 	}
-	*/}}
 
 	log.Printf("Start listening proxy service on port %s\n", cfg.Port)
 	if err := server.ListenAndServe("tcp", ":"+cfg.Port); err != nil {
diff --git a/vendor/github.com/armon/go-socks5/socks5.go b/vendor/github.com/armon/go-socks5/socks5.go
index a17be68..6d58902 100644
--- a/vendor/github.com/armon/go-socks5/socks5.go
+++ b/vendor/github.com/armon/go-socks5/socks5.go
@@ -55,6 +55,7 @@ type Config struct {
 type Server struct {
 	config      *Config
 	authMethods map[uint8]Authenticator
+	isIPAllowed func(net.IP) bool
 }
 
 // New creates a new Server and potentially returns an error
@@ -93,6 +94,11 @@ func New(conf *Config) (*Server, error) {
 		server.authMethods[a.GetCode()] = a
 	}
 
+	// Set default IP whitelist function
+	server.isIPAllowed = func(ip net.IP) bool {
+		return true // default allow all IPs
+	}
+
 	return server, nil
 }
 
@@ -117,11 +123,37 @@ func (s *Server) Serve(l net.Listener) error {
 	return nil
 }
 
+// SetIPWhitelist sets the function to check if a given IP is allowed
+func (s *Server) SetIPWhitelist(allowedIPs []net.IP) {
+	s.isIPAllowed = func(ip net.IP) bool {
+		for _, allowedIP := range allowedIPs {
+			if ip.Equal(allowedIP) {
+				return true
+			}
+		}
+		return false
+	}
+}
+
 // ServeConn is used to serve a single connection.
 func (s *Server) ServeConn(conn net.Conn) error {
 	defer conn.Close()
 	bufConn := bufio.NewReader(conn)
 
+	// Check client IP against whitelist
+	clientIP, _, err := net.SplitHostPort(conn.RemoteAddr().String())
+	if err != nil {
+		s.config.Logger.Printf("[ERR] socks: Failed to get client IP address: %v", err)
+		return err
+	}
+	ip := net.ParseIP(clientIP)
+	if s.isIPAllowed(ip) {
+		s.config.Logger.Printf("[INFO] socks: Connection from allowed IP address: %s", clientIP)
+	} else {
+		s.config.Logger.Printf("[WARN] socks: Connection from not allowed IP address: %s", clientIP)
+		return fmt.Errorf("connection from not allowed IP address")
+	}
+	
 	// Read the version byte
 	version := []byte{0}
 	if _, err := bufConn.Read(version); err != nil {
diff --git a/vendor/modules.txt b/vendor/modules.txt
index c664b3c..7429c12 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -1,4 +1,4 @@
-# github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5
+# github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 => github.com/serjs/go-socks5 v0.0.0-20250923183437-3920b97ee0d2
 ## explicit
 github.com/armon/go-socks5
 # github.com/caarlos0/env/v6 v6.10.1
@@ -7,3 +7,4 @@ github.com/caarlos0/env/v6
 # golang.org/x/net v0.38.0
 ## explicit; go 1.23.0
 golang.org/x/net/context
+# github.com/armon/go-socks5 => github.com/serjs/go-socks5 v0.0.0-20250923183437-3920b97ee0d2