diff --git a/client.go b/client.go
index e9161e9..fd5763a 100644
--- a/client.go
+++ b/client.go
@@ -88,8 +88,7 @@ type Client struct {
 	// Store user defined options and states
 	config Config
 	// Session gather data that can be accessed by users of this library
-	Session *Session
-	// TCP level connection / can be replaced by a TLS session after starttls
+	Session   *Session
 	transport Transport
 	// Router is used to dispatch packets
 	router *Router
@@ -139,12 +138,13 @@ func NewClient(config Config, r *Router) (c *Client, err error) {
 	c = new(Client)
 	c.config = config
 	c.router = r
-	c.transport = &XMPPTransport{}
 
 	if c.config.ConnectTimeout == 0 {
 		c.config.ConnectTimeout = 15 // 15 second as default
 	}
 
+	c.transport = &XMPPTransport{Config: config.TransportConfiguration}
+
 	return
 }
 
@@ -160,7 +160,7 @@ func (c *Client) Connect() error {
 func (c *Client) Resume(state SMState) error {
 	var err error
 
-	err = c.transport.Connect(c.config.Address, c.config)
+	err = c.transport.Connect(c.config.Address)
 	if err != nil {
 		return err
 	}
diff --git a/config.go b/config.go
index 8ce304f..c4ff97f 100644
--- a/config.go
+++ b/config.go
@@ -1,12 +1,15 @@
 package xmpp
 
 import (
-	"crypto/tls"
 	"io"
 	"os"
 )
 
 type Config struct {
+	// TransportConfiguration must not be modified after having been passed to NewClient. Any
+	// changes made after connecting are ignored.
+	TransportConfiguration
+
 	Address        string
 	Jid            string
 	parsedJid      *Jid // For easier manipulation
@@ -14,9 +17,6 @@ type Config struct {
 	StreamLogger   *os.File // Used for debugging
 	Lang           string   // TODO: should default to 'en'
 	ConnectTimeout int      // Client timeout in seconds. Default to 15
-	// tls.Config must not be modified after having been passed to NewClient. Any
-	// changes made after connecting are ignored.
-	TLSConfig *tls.Config
 	// Insecure can be set to true to allow to open a session without TLS. If TLS
 	// is supported on the server, we will still try to use it.
 	Insecure      bool
diff --git a/session.go b/session.go
index c7a1454..191c2c3 100644
--- a/session.go
+++ b/session.go
@@ -132,7 +132,7 @@ func (s *Session) startTlsIfSupported(transport Transport, domain string, o Conf
 			return
 		}
 
-		s.err = transport.StartTLS(domain, o)
+		s.err = transport.StartTLS(domain)
 
 		if s.err == nil {
 			s.TlsEnabled = true
diff --git a/transport.go b/transport.go
index 0ac7195..296cec1 100644
--- a/transport.go
+++ b/transport.go
@@ -6,10 +6,17 @@ import (
 	"time"
 )
 
+type TransportConfiguration struct {
+	ConnectTimeout int // Client timeout in seconds. Default to 15
+	// tls.Config must not be modified after having been passed to NewClient. Any
+	// changes made after connecting are ignored.
+	TLSConfig *tls.Config
+}
+
 type Transport interface {
-	Connect(address string, c Config) error
+	Connect(address string) error
 	DoesStartTLS() bool
-	StartTLS(domain string, c Config) error
+	StartTLS(domain string) error
 
 	Read(p []byte) (n int, err error)
 	Write(p []byte) (n int, err error)
@@ -18,15 +25,16 @@ type Transport interface {
 
 // XMPPTransport implements the XMPP native TCP transport
 type XMPPTransport struct {
+	Config    TransportConfiguration
 	TLSConfig *tls.Config
 	// TCP level connection / can be replaced by a TLS session after starttls
 	conn net.Conn
 }
 
-func (t *XMPPTransport) Connect(address string, c Config) error {
+func (t *XMPPTransport) Connect(address string) error {
 	var err error
 
-	t.conn, err = net.DialTimeout("tcp", address, time.Duration(c.ConnectTimeout)*time.Second)
+	t.conn, err = net.DialTimeout("tcp", address, time.Duration(t.Config.ConnectTimeout)*time.Second)
 	return err
 }
 
@@ -34,17 +42,13 @@ func (t XMPPTransport) DoesStartTLS() bool {
 	return true
 }
 
-func (t *XMPPTransport) StartTLS(domain string, c Config) error {
-	if t.TLSConfig == nil {
-		if c.TLSConfig != nil {
-			t.TLSConfig = c.TLSConfig
-		} else {
-			t.TLSConfig = &tls.Config{}
-		}
+func (t *XMPPTransport) StartTLS(domain string) error {
+	if t.Config.TLSConfig == nil {
+		t.Config.TLSConfig = &tls.Config{}
 	}
 
-	if t.TLSConfig.ServerName == "" {
-		t.TLSConfig.ServerName = domain
+	if t.Config.TLSConfig.ServerName == "" {
+		t.Config.TLSConfig.ServerName = domain
 	}
 	tlsConn := tls.Client(t.conn, t.TLSConfig)
 	// We convert existing connection to TLS