diff --git a/infra/conf/transport_internet.go b/infra/conf/transport_internet.go
index 805a674e..908a95d3 100644
--- a/infra/conf/transport_internet.go
+++ b/infra/conf/transport_internet.go
@@ -392,7 +392,6 @@ type TLSConfig struct {
 	MinVersion                           string           `json:"minVersion"`
 	MaxVersion                           string           `json:"maxVersion"`
 	CipherSuites                         string           `json:"cipherSuites"`
-	PreferServerCipherSuites             bool             `json:"preferServerCipherSuites"`
 	Fingerprint                          string           `json:"fingerprint"`
 	RejectUnknownSNI                     bool             `json:"rejectUnknownSni"`
 	PinnedPeerCertificateChainSha256     *[]string        `json:"pinnedPeerCertificateChainSha256"`
@@ -424,7 +423,6 @@ func (c *TLSConfig) Build() (proto.Message, error) {
 	config.MinVersion = c.MinVersion
 	config.MaxVersion = c.MaxVersion
 	config.CipherSuites = c.CipherSuites
-	config.PreferServerCipherSuites = c.PreferServerCipherSuites
 	config.Fingerprint = strings.ToLower(c.Fingerprint)
 	if config.Fingerprint != "" && tls.GetFingerprint(config.Fingerprint) == nil {
 		return nil, newError(`unknown fingerprint: `, config.Fingerprint)
diff --git a/transport/internet/http/dialer.go b/transport/internet/http/dialer.go
index 513962d3..acccd0b7 100644
--- a/transport/internet/http/dialer.go
+++ b/transport/internet/http/dialer.go
@@ -97,13 +97,10 @@ func getHTTPClient(ctx context.Context, dest net.Destination, streamSettings *in
 					return nil, err
 				}
 			}
-			negotiatedProtocol, negotiatedProtocolIsMutual := cn.NegotiatedProtocol()
+			negotiatedProtocol := cn.NegotiatedProtocol()
 			if negotiatedProtocol != http2.NextProtoTLS {
 				return nil, newError("http2: unexpected ALPN protocol " + negotiatedProtocol + "; want q" + http2.NextProtoTLS).AtError()
 			}
-			if !negotiatedProtocolIsMutual {
-				return nil, newError("http2: could not negotiate protocol mutually").AtError()
-			}
 			return cn, nil
 		},
 	}
diff --git a/transport/internet/tls/config.go b/transport/internet/tls/config.go
index 03c43a9e..36aca803 100644
--- a/transport/internet/tls/config.go
+++ b/transport/internet/tls/config.go
@@ -368,8 +368,6 @@ func (c *Config) GetTLSConfig(opts ...Option) *tls.Config {
 		}
 	}
 
-	config.PreferServerCipherSuites = c.PreferServerCipherSuites
-
 	if len(c.MasterKeyLog) > 0 && c.MasterKeyLog != "none" {
 		writer, err := os.OpenFile(c.MasterKeyLog, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0644)
 		if err != nil {
diff --git a/transport/internet/tls/config.pb.go b/transport/internet/tls/config.pb.go
index 0e616ae8..d8c9a423 100644
--- a/transport/internet/tls/config.pb.go
+++ b/transport/internet/tls/config.pb.go
@@ -194,6 +194,9 @@ type Config struct {
 	// Specify cipher suites, except for TLS 1.3.
 	CipherSuites string `protobuf:"bytes,9,opt,name=cipher_suites,json=cipherSuites,proto3" json:"cipher_suites,omitempty"`
 	// Whether the server selects its most preferred ciphersuite.
+	// Deprecated: crypto/tls has ignored this field.
+	//
+	// Deprecated: Marked as deprecated in transport/internet/tls/config.proto.
 	PreferServerCipherSuites bool `protobuf:"varint,10,opt,name=prefer_server_cipher_suites,json=preferServerCipherSuites,proto3" json:"prefer_server_cipher_suites,omitempty"`
 	// TLS Client Hello fingerprint (uTLS).
 	Fingerprint      string `protobuf:"bytes,11,opt,name=fingerprint,proto3" json:"fingerprint,omitempty"`
@@ -306,6 +309,7 @@ func (x *Config) GetCipherSuites() string {
 	return ""
 }
 
+// Deprecated: Marked as deprecated in transport/internet/tls/config.proto.
 func (x *Config) GetPreferServerCipherSuites() bool {
 	if x != nil {
 		return x.PreferServerCipherSuites
@@ -377,7 +381,7 @@ var file_transport_internet_tls_config_proto_rawDesc = []byte{
 	0x43, 0x49, 0x50, 0x48, 0x45, 0x52, 0x4d, 0x45, 0x4e, 0x54, 0x10, 0x00, 0x12, 0x14, 0x0a, 0x10,
 	0x41, 0x55, 0x54, 0x48, 0x4f, 0x52, 0x49, 0x54, 0x59, 0x5f, 0x56, 0x45, 0x52, 0x49, 0x46, 0x59,
 	0x10, 0x01, 0x12, 0x13, 0x0a, 0x0f, 0x41, 0x55, 0x54, 0x48, 0x4f, 0x52, 0x49, 0x54, 0x59, 0x5f,
-	0x49, 0x53, 0x53, 0x55, 0x45, 0x10, 0x02, 0x22, 0xf2, 0x05, 0x0a, 0x06, 0x43, 0x6f, 0x6e, 0x66,
+	0x49, 0x53, 0x53, 0x55, 0x45, 0x10, 0x02, 0x22, 0xf6, 0x05, 0x0a, 0x06, 0x43, 0x6f, 0x6e, 0x66,
 	0x69, 0x67, 0x12, 0x25, 0x0a, 0x0e, 0x61, 0x6c, 0x6c, 0x6f, 0x77, 0x5f, 0x69, 0x6e, 0x73, 0x65,
 	0x63, 0x75, 0x72, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x08, 0x52, 0x0d, 0x61, 0x6c, 0x6c, 0x6f,
 	0x77, 0x49, 0x6e, 0x73, 0x65, 0x63, 0x75, 0x72, 0x65, 0x12, 0x4a, 0x0a, 0x0b, 0x63, 0x65, 0x72,
@@ -402,37 +406,37 @@ var file_transport_internet_tls_config_proto_rawDesc = []byte{
 	0x76, 0x65, 0x72, 0x73, 0x69, 0x6f, 0x6e, 0x18, 0x08, 0x20, 0x01, 0x28, 0x09, 0x52, 0x0a, 0x6d,
 	0x61, 0x78, 0x56, 0x65, 0x72, 0x73, 0x69, 0x6f, 0x6e, 0x12, 0x23, 0x0a, 0x0d, 0x63, 0x69, 0x70,
 	0x68, 0x65, 0x72, 0x5f, 0x73, 0x75, 0x69, 0x74, 0x65, 0x73, 0x18, 0x09, 0x20, 0x01, 0x28, 0x09,
-	0x52, 0x0c, 0x63, 0x69, 0x70, 0x68, 0x65, 0x72, 0x53, 0x75, 0x69, 0x74, 0x65, 0x73, 0x12, 0x3d,
+	0x52, 0x0c, 0x63, 0x69, 0x70, 0x68, 0x65, 0x72, 0x53, 0x75, 0x69, 0x74, 0x65, 0x73, 0x12, 0x41,
 	0x0a, 0x1b, 0x70, 0x72, 0x65, 0x66, 0x65, 0x72, 0x5f, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x5f,
 	0x63, 0x69, 0x70, 0x68, 0x65, 0x72, 0x5f, 0x73, 0x75, 0x69, 0x74, 0x65, 0x73, 0x18, 0x0a, 0x20,
-	0x01, 0x28, 0x08, 0x52, 0x18, 0x70, 0x72, 0x65, 0x66, 0x65, 0x72, 0x53, 0x65, 0x72, 0x76, 0x65,
-	0x72, 0x43, 0x69, 0x70, 0x68, 0x65, 0x72, 0x53, 0x75, 0x69, 0x74, 0x65, 0x73, 0x12, 0x20, 0x0a,
-	0x0b, 0x66, 0x69, 0x6e, 0x67, 0x65, 0x72, 0x70, 0x72, 0x69, 0x6e, 0x74, 0x18, 0x0b, 0x20, 0x01,
-	0x28, 0x09, 0x52, 0x0b, 0x66, 0x69, 0x6e, 0x67, 0x65, 0x72, 0x70, 0x72, 0x69, 0x6e, 0x74, 0x12,
-	0x2c, 0x0a, 0x12, 0x72, 0x65, 0x6a, 0x65, 0x63, 0x74, 0x5f, 0x75, 0x6e, 0x6b, 0x6e, 0x6f, 0x77,
-	0x6e, 0x5f, 0x73, 0x6e, 0x69, 0x18, 0x0c, 0x20, 0x01, 0x28, 0x08, 0x52, 0x10, 0x72, 0x65, 0x6a,
-	0x65, 0x63, 0x74, 0x55, 0x6e, 0x6b, 0x6e, 0x6f, 0x77, 0x6e, 0x53, 0x6e, 0x69, 0x12, 0x4e, 0x0a,
-	0x24, 0x70, 0x69, 0x6e, 0x6e, 0x65, 0x64, 0x5f, 0x70, 0x65, 0x65, 0x72, 0x5f, 0x63, 0x65, 0x72,
-	0x74, 0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x5f, 0x63, 0x68, 0x61, 0x69, 0x6e, 0x5f, 0x73,
-	0x68, 0x61, 0x32, 0x35, 0x36, 0x18, 0x0d, 0x20, 0x03, 0x28, 0x0c, 0x52, 0x20, 0x70, 0x69, 0x6e,
-	0x6e, 0x65, 0x64, 0x50, 0x65, 0x65, 0x72, 0x43, 0x65, 0x72, 0x74, 0x69, 0x66, 0x69, 0x63, 0x61,
-	0x74, 0x65, 0x43, 0x68, 0x61, 0x69, 0x6e, 0x53, 0x68, 0x61, 0x32, 0x35, 0x36, 0x12, 0x57, 0x0a,
-	0x29, 0x70, 0x69, 0x6e, 0x6e, 0x65, 0x64, 0x5f, 0x70, 0x65, 0x65, 0x72, 0x5f, 0x63, 0x65, 0x72,
-	0x74, 0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x5f, 0x70, 0x75, 0x62, 0x6c, 0x69, 0x63, 0x5f,
-	0x6b, 0x65, 0x79, 0x5f, 0x73, 0x68, 0x61, 0x32, 0x35, 0x36, 0x18, 0x0e, 0x20, 0x03, 0x28, 0x0c,
-	0x52, 0x24, 0x70, 0x69, 0x6e, 0x6e, 0x65, 0x64, 0x50, 0x65, 0x65, 0x72, 0x43, 0x65, 0x72, 0x74,
-	0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x50, 0x75, 0x62, 0x6c, 0x69, 0x63, 0x4b, 0x65, 0x79,
-	0x53, 0x68, 0x61, 0x32, 0x35, 0x36, 0x12, 0x24, 0x0a, 0x0e, 0x6d, 0x61, 0x73, 0x74, 0x65, 0x72,
-	0x5f, 0x6b, 0x65, 0x79, 0x5f, 0x6c, 0x6f, 0x67, 0x18, 0x0f, 0x20, 0x01, 0x28, 0x09, 0x52, 0x0c,
-	0x6d, 0x61, 0x73, 0x74, 0x65, 0x72, 0x4b, 0x65, 0x79, 0x4c, 0x6f, 0x67, 0x42, 0x73, 0x0a, 0x1f,
-	0x63, 0x6f, 0x6d, 0x2e, 0x78, 0x72, 0x61, 0x79, 0x2e, 0x74, 0x72, 0x61, 0x6e, 0x73, 0x70, 0x6f,
-	0x72, 0x74, 0x2e, 0x69, 0x6e, 0x74, 0x65, 0x72, 0x6e, 0x65, 0x74, 0x2e, 0x74, 0x6c, 0x73, 0x50,
-	0x01, 0x5a, 0x30, 0x67, 0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x78, 0x74,
-	0x6c, 0x73, 0x2f, 0x78, 0x72, 0x61, 0x79, 0x2d, 0x63, 0x6f, 0x72, 0x65, 0x2f, 0x74, 0x72, 0x61,
-	0x6e, 0x73, 0x70, 0x6f, 0x72, 0x74, 0x2f, 0x69, 0x6e, 0x74, 0x65, 0x72, 0x6e, 0x65, 0x74, 0x2f,
-	0x74, 0x6c, 0x73, 0xaa, 0x02, 0x1b, 0x58, 0x72, 0x61, 0x79, 0x2e, 0x54, 0x72, 0x61, 0x6e, 0x73,
-	0x70, 0x6f, 0x72, 0x74, 0x2e, 0x49, 0x6e, 0x74, 0x65, 0x72, 0x6e, 0x65, 0x74, 0x2e, 0x54, 0x6c,
-	0x73, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+	0x01, 0x28, 0x08, 0x42, 0x02, 0x18, 0x01, 0x52, 0x18, 0x70, 0x72, 0x65, 0x66, 0x65, 0x72, 0x53,
+	0x65, 0x72, 0x76, 0x65, 0x72, 0x43, 0x69, 0x70, 0x68, 0x65, 0x72, 0x53, 0x75, 0x69, 0x74, 0x65,
+	0x73, 0x12, 0x20, 0x0a, 0x0b, 0x66, 0x69, 0x6e, 0x67, 0x65, 0x72, 0x70, 0x72, 0x69, 0x6e, 0x74,
+	0x18, 0x0b, 0x20, 0x01, 0x28, 0x09, 0x52, 0x0b, 0x66, 0x69, 0x6e, 0x67, 0x65, 0x72, 0x70, 0x72,
+	0x69, 0x6e, 0x74, 0x12, 0x2c, 0x0a, 0x12, 0x72, 0x65, 0x6a, 0x65, 0x63, 0x74, 0x5f, 0x75, 0x6e,
+	0x6b, 0x6e, 0x6f, 0x77, 0x6e, 0x5f, 0x73, 0x6e, 0x69, 0x18, 0x0c, 0x20, 0x01, 0x28, 0x08, 0x52,
+	0x10, 0x72, 0x65, 0x6a, 0x65, 0x63, 0x74, 0x55, 0x6e, 0x6b, 0x6e, 0x6f, 0x77, 0x6e, 0x53, 0x6e,
+	0x69, 0x12, 0x4e, 0x0a, 0x24, 0x70, 0x69, 0x6e, 0x6e, 0x65, 0x64, 0x5f, 0x70, 0x65, 0x65, 0x72,
+	0x5f, 0x63, 0x65, 0x72, 0x74, 0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x5f, 0x63, 0x68, 0x61,
+	0x69, 0x6e, 0x5f, 0x73, 0x68, 0x61, 0x32, 0x35, 0x36, 0x18, 0x0d, 0x20, 0x03, 0x28, 0x0c, 0x52,
+	0x20, 0x70, 0x69, 0x6e, 0x6e, 0x65, 0x64, 0x50, 0x65, 0x65, 0x72, 0x43, 0x65, 0x72, 0x74, 0x69,
+	0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x43, 0x68, 0x61, 0x69, 0x6e, 0x53, 0x68, 0x61, 0x32, 0x35,
+	0x36, 0x12, 0x57, 0x0a, 0x29, 0x70, 0x69, 0x6e, 0x6e, 0x65, 0x64, 0x5f, 0x70, 0x65, 0x65, 0x72,
+	0x5f, 0x63, 0x65, 0x72, 0x74, 0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x5f, 0x70, 0x75, 0x62,
+	0x6c, 0x69, 0x63, 0x5f, 0x6b, 0x65, 0x79, 0x5f, 0x73, 0x68, 0x61, 0x32, 0x35, 0x36, 0x18, 0x0e,
+	0x20, 0x03, 0x28, 0x0c, 0x52, 0x24, 0x70, 0x69, 0x6e, 0x6e, 0x65, 0x64, 0x50, 0x65, 0x65, 0x72,
+	0x43, 0x65, 0x72, 0x74, 0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x50, 0x75, 0x62, 0x6c, 0x69,
+	0x63, 0x4b, 0x65, 0x79, 0x53, 0x68, 0x61, 0x32, 0x35, 0x36, 0x12, 0x24, 0x0a, 0x0e, 0x6d, 0x61,
+	0x73, 0x74, 0x65, 0x72, 0x5f, 0x6b, 0x65, 0x79, 0x5f, 0x6c, 0x6f, 0x67, 0x18, 0x0f, 0x20, 0x01,
+	0x28, 0x09, 0x52, 0x0c, 0x6d, 0x61, 0x73, 0x74, 0x65, 0x72, 0x4b, 0x65, 0x79, 0x4c, 0x6f, 0x67,
+	0x42, 0x73, 0x0a, 0x1f, 0x63, 0x6f, 0x6d, 0x2e, 0x78, 0x72, 0x61, 0x79, 0x2e, 0x74, 0x72, 0x61,
+	0x6e, 0x73, 0x70, 0x6f, 0x72, 0x74, 0x2e, 0x69, 0x6e, 0x74, 0x65, 0x72, 0x6e, 0x65, 0x74, 0x2e,
+	0x74, 0x6c, 0x73, 0x50, 0x01, 0x5a, 0x30, 0x67, 0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f,
+	0x6d, 0x2f, 0x78, 0x74, 0x6c, 0x73, 0x2f, 0x78, 0x72, 0x61, 0x79, 0x2d, 0x63, 0x6f, 0x72, 0x65,
+	0x2f, 0x74, 0x72, 0x61, 0x6e, 0x73, 0x70, 0x6f, 0x72, 0x74, 0x2f, 0x69, 0x6e, 0x74, 0x65, 0x72,
+	0x6e, 0x65, 0x74, 0x2f, 0x74, 0x6c, 0x73, 0xaa, 0x02, 0x1b, 0x58, 0x72, 0x61, 0x79, 0x2e, 0x54,
+	0x72, 0x61, 0x6e, 0x73, 0x70, 0x6f, 0x72, 0x74, 0x2e, 0x49, 0x6e, 0x74, 0x65, 0x72, 0x6e, 0x65,
+	0x74, 0x2e, 0x54, 0x6c, 0x73, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (
diff --git a/transport/internet/tls/config.proto b/transport/internet/tls/config.proto
index b1c26a4c..12c7b7cb 100644
--- a/transport/internet/tls/config.proto
+++ b/transport/internet/tls/config.proto
@@ -63,7 +63,8 @@ message Config {
   string cipher_suites = 9;
 
   // Whether the server selects its most preferred ciphersuite.
-  bool prefer_server_cipher_suites = 10;
+  // Deprecated: crypto/tls has ignored this field.
+  bool prefer_server_cipher_suites = 10 [deprecated = true];
 
   // TLS Client Hello fingerprint (uTLS).
   string fingerprint = 11;
diff --git a/transport/internet/tls/tls.go b/transport/internet/tls/tls.go
index 73631ef9..25889cb1 100644
--- a/transport/internet/tls/tls.go
+++ b/transport/internet/tls/tls.go
@@ -18,10 +18,11 @@ type Interface interface {
 	net.Conn
 	HandshakeContext(ctx context.Context) error
 	VerifyHostname(host string) error
-	NegotiatedProtocol() (name string, mutual bool)
+	NegotiatedProtocol() string
 }
 
 var _ buf.Writer = (*Conn)(nil)
+var _ Interface = (*Conn)(nil)
 
 type Conn struct {
 	*tls.Conn
@@ -55,9 +56,9 @@ func (c *Conn) HandshakeAddressContext(ctx context.Context) net.Address {
 	return net.ParseAddress(state.ServerName)
 }
 
-func (c *Conn) NegotiatedProtocol() (name string, mutual bool) {
+func (c *Conn) NegotiatedProtocol() string {
 	state := c.ConnectionState()
-	return state.NegotiatedProtocol, state.NegotiatedProtocolIsMutual
+	return state.NegotiatedProtocol
 }
 
 // Client initiates a TLS client handshake on the given connection.
@@ -76,6 +77,8 @@ type UConn struct {
 	*utls.UConn
 }
 
+var _ Interface = (*UConn)(nil)
+
 func (c *UConn) Close() error {
 	timer := time.AfterFunc(tlsCloseTimeout, func() {
 		c.Conn.NetConn().Close()
@@ -122,9 +125,9 @@ func (c *UConn) WebsocketHandshakeContext(ctx context.Context) error {
 	return c.HandshakeContext(ctx)
 }
 
-func (c *UConn) NegotiatedProtocol() (name string, mutual bool) {
+func (c *UConn) NegotiatedProtocol() string {
 	state := c.ConnectionState()
-	return state.NegotiatedProtocol, state.NegotiatedProtocolIsMutual
+	return state.NegotiatedProtocol
 }
 
 func UClient(c net.Conn, config *tls.Config, fingerprint *utls.ClientHelloID) net.Conn {