diff --git a/socks.go b/socks.go
index 3f7c76c..1f9a625 100755
--- a/socks.go
+++ b/socks.go
@@ -16,14 +16,15 @@ const (
 	addrTypeIPv6   = 0x04
 )
 
-type dialFunc func(network, addr string) (net.Conn, error)
+// DialFunc the function dial to remote
+type DialFunc func(network, addr string) (net.Conn, error)
 
 // Conn present a client connection
 type Conn struct {
 	net.Conn
 	// the function to dial to upstream server
 	// when nil, use net.Dial
-	Dial dialFunc
+	Dial DialFunc
 	// username for socks5 server
 	Username string
 	// password
diff --git a/socks4.go b/socks4.go
index 7472b90..6e9b1de 100755
--- a/socks4.go
+++ b/socks4.go
@@ -34,7 +34,7 @@ byte | 0  |  1  | 2 | 3 | 4 | 5 | 6| 7 |
 type socks4Conn struct {
 	serverConn net.Conn
 	clientConn net.Conn
-	dial       dialFunc
+	dial       DialFunc
 }
 
 func (s4 *socks4Conn) Serve() {
diff --git a/socks5.go b/socks5.go
index 13f8ef1..0535555 100755
--- a/socks5.go
+++ b/socks5.go
@@ -56,7 +56,7 @@ type socks5Conn struct {
 	//addr        string
 	clientConn net.Conn
 	serverConn net.Conn
-	dial       dialFunc
+	dial       DialFunc
 }
 
 func (s5 *socks5Conn) Serve() {