diff --git a/internal/handshake/aead.go b/internal/handshake/aead.go
index f11372c84..07ce74f74 100644
--- a/internal/handshake/aead.go
+++ b/internal/handshake/aead.go
@@ -8,7 +8,6 @@ import (
 )
 
 type sealer struct {
-	iv          []byte
 	aead        cipher.AEAD
 	hpEncrypter cipher.Block
 
@@ -22,9 +21,8 @@ type sealer struct {
 
 var _ Sealer = &sealer{}
 
-func newSealer(aead cipher.AEAD, iv []byte, hpEncrypter cipher.Block, is1RTT bool) Sealer {
+func newSealer(aead cipher.AEAD, hpEncrypter cipher.Block, is1RTT bool) Sealer {
 	return &sealer{
-		iv:          iv,
 		aead:        aead,
 		nonceBuf:    make([]byte, aead.NonceSize()),
 		is1RTT:      is1RTT,
@@ -35,14 +33,9 @@ func newSealer(aead cipher.AEAD, iv []byte, hpEncrypter cipher.Block, is1RTT boo
 
 func (s *sealer) Seal(dst, src []byte, pn protocol.PacketNumber, ad []byte) []byte {
 	binary.BigEndian.PutUint64(s.nonceBuf[len(s.nonceBuf)-8:], uint64(pn))
-	for i := 0; i < len(s.nonceBuf); i++ {
-		s.nonceBuf[i] ^= s.iv[i]
-	}
-	sealed := s.aead.Seal(dst, s.nonceBuf, src, ad)
-	for i := 0; i < len(s.nonceBuf); i++ {
-		s.nonceBuf[i] = 0
-	}
-	return sealed
+	// The AEAD we're using here will be the qtls.aeadAESGCM13.
+	// It uses the nonce provided here and XOR it with the IV.
+	return s.aead.Seal(dst, s.nonceBuf, src, ad)
 }
 
 func (s *sealer) EncryptHeader(sample []byte, firstByte *byte, pnBytes []byte) {
@@ -65,7 +58,6 @@ func (s *sealer) Overhead() int {
 }
 
 type opener struct {
-	iv          []byte
 	aead        cipher.AEAD
 	pnDecrypter cipher.Block
 
@@ -79,9 +71,8 @@ type opener struct {
 
 var _ Opener = &opener{}
 
-func newOpener(aead cipher.AEAD, iv []byte, pnDecrypter cipher.Block, is1RTT bool) Opener {
+func newOpener(aead cipher.AEAD, pnDecrypter cipher.Block, is1RTT bool) Opener {
 	return &opener{
-		iv:          iv,
 		aead:        aead,
 		nonceBuf:    make([]byte, aead.NonceSize()),
 		is1RTT:      is1RTT,
@@ -92,14 +83,9 @@ func newOpener(aead cipher.AEAD, iv []byte, pnDecrypter cipher.Block, is1RTT boo
 
 func (o *opener) Open(dst, src []byte, pn protocol.PacketNumber, ad []byte) ([]byte, error) {
 	binary.BigEndian.PutUint64(o.nonceBuf[len(o.nonceBuf)-8:], uint64(pn))
-	for i := 0; i < len(o.nonceBuf); i++ {
-		o.nonceBuf[i] ^= o.iv[i]
-	}
-	opened, err := o.aead.Open(dst, o.nonceBuf, src, ad)
-	for i := 0; i < len(o.nonceBuf); i++ {
-		o.nonceBuf[i] = 0
-	}
-	return opened, err
+	// The AEAD we're using here will be the qtls.aeadAESGCM13.
+	// It uses the nonce provided here and XOR it with the IV.
+	return o.aead.Open(dst, o.nonceBuf, src, ad)
 }
 
 func (o *opener) DecryptHeader(sample []byte, firstByte *byte, pnBytes []byte) {
diff --git a/internal/handshake/aead_test.go b/internal/handshake/aead_test.go
index 3aa2580cf..2f7bfbac1 100644
--- a/internal/handshake/aead_test.go
+++ b/internal/handshake/aead_test.go
@@ -12,19 +12,19 @@ import (
 var _ = Describe("AEAD", func() {
 	getSealerAndOpener := func(is1RTT bool) (Sealer, Opener) {
 		key := make([]byte, 16)
-		pnKey := make([]byte, 16)
+		hpKey := make([]byte, 16)
 		rand.Read(key)
-		rand.Read(pnKey)
+		rand.Read(hpKey)
 		block, err := aes.NewCipher(key)
 		Expect(err).ToNot(HaveOccurred())
 		aead, err := cipher.NewGCM(block)
 		Expect(err).ToNot(HaveOccurred())
-		pnBlock, err := aes.NewCipher(pnKey)
+		hpBlock, err := aes.NewCipher(hpKey)
 		Expect(err).ToNot(HaveOccurred())
 
 		iv := make([]byte, 12)
 		rand.Read(iv)
-		return newSealer(aead, iv, pnBlock, is1RTT), newOpener(aead, iv, pnBlock, is1RTT)
+		return newSealer(aead, hpBlock, is1RTT), newOpener(aead, hpBlock, is1RTT)
 	}
 
 	Context("message encryption", func() {
diff --git a/internal/handshake/crypto_setup.go b/internal/handshake/crypto_setup.go
index f3e39a343..0ea25c204 100644
--- a/internal/handshake/crypto_setup.go
+++ b/internal/handshake/crypto_setup.go
@@ -419,7 +419,6 @@ func (h *cryptoSetup) SetReadKey(suite *qtls.CipherSuite, trafficSecret []byte)
 	}
 	opener := newOpener(
 		suite.AEAD(key, iv),
-		iv,
 		hpDecrypter,
 		h.readEncLevel == protocol.Encryption1RTT,
 	)
@@ -449,7 +448,6 @@ func (h *cryptoSetup) SetWriteKey(suite *qtls.CipherSuite, trafficSecret []byte)
 	}
 	sealer := newSealer(
 		suite.AEAD(key, iv),
-		iv,
 		hpEncrypter,
 		h.writeEncLevel == protocol.Encryption1RTT,
 	)
diff --git a/internal/handshake/initial_aead.go b/internal/handshake/initial_aead.go
index a2e3b0db4..90334a1b0 100644
--- a/internal/handshake/initial_aead.go
+++ b/internal/handshake/initial_aead.go
@@ -3,7 +3,6 @@ package handshake
 import (
 	"crypto"
 	"crypto/aes"
-	"crypto/cipher"
 
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 	"github.com/marten-seemann/qtls"
@@ -25,31 +24,17 @@ func NewInitialAEAD(connID protocol.ConnectionID, pers protocol.Perspective) (Se
 	myKey, myHPKey, myIV := computeInitialKeyAndIV(mySecret)
 	otherKey, otherHPKey, otherIV := computeInitialKeyAndIV(otherSecret)
 
-	encrypterCipher, err := aes.NewCipher(myKey)
-	if err != nil {
-		return nil, nil, err
-	}
-	encrypter, err := cipher.NewGCM(encrypterCipher)
-	if err != nil {
-		return nil, nil, err
-	}
+	encrypter := qtls.AEADAESGCM13(myKey, myIV)
 	hpEncrypter, err := aes.NewCipher(myHPKey)
 	if err != nil {
 		return nil, nil, err
 	}
-	decrypterCipher, err := aes.NewCipher(otherKey)
-	if err != nil {
-		return nil, nil, err
-	}
-	decrypter, err := cipher.NewGCM(decrypterCipher)
-	if err != nil {
-		return nil, nil, err
-	}
+	decrypter := qtls.AEADAESGCM13(otherKey, otherIV)
 	hpDecrypter, err := aes.NewCipher(otherHPKey)
 	if err != nil {
 		return nil, nil, err
 	}
-	return newSealer(encrypter, myIV, hpEncrypter, false), newOpener(decrypter, otherIV, hpDecrypter, false), nil
+	return newSealer(encrypter, hpEncrypter, false), newOpener(decrypter, hpDecrypter, false), nil
 }
 
 func computeSecrets(connID protocol.ConnectionID) (clientSecret, serverSecret []byte) {
diff --git a/vendor/github.com/marten-seemann/qtls/cipher_suites.go b/vendor/github.com/marten-seemann/qtls/cipher_suites.go
index 3bbc0b90d..781c32282 100644
--- a/vendor/github.com/marten-seemann/qtls/cipher_suites.go
+++ b/vendor/github.com/marten-seemann/qtls/cipher_suites.go
@@ -250,6 +250,11 @@ func aeadAESGCM12(key, fixedNonce []byte) cipher.AEAD {
 	return ret
 }
 
+// AEADAESGCM13 creates a new AES-GCM AEAD for TLS 1.3
+func AEADAESGCM13(key, fixedNonce []byte) cipher.AEAD {
+	return aeadAESGCM13(key, fixedNonce)
+}
+
 func aeadAESGCM13(key, fixedNonce []byte) cipher.AEAD {
 	aes, err := aes.NewCipher(key)
 	if err != nil {
diff --git a/vendor/vendor.json b/vendor/vendor.json
index c5afee206..d6691a773 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -45,10 +45,10 @@
 			"revisionTime": "2018-11-11T22:04:28Z"
 		},
 		{
-			"checksumSHA1": "FDYRKDgqEto8ahW65hY3RruQLmg=",
+			"checksumSHA1": "dpjM/eonkDPExO4QWg4+R0wZPCs=",
 			"path": "github.com/marten-seemann/qtls",
-			"revision": "061d608f3d22ea089c4c9039e1216eea999b9341",
-			"revisionTime": "2018-12-25T08:07:48Z"
+			"revision": "26b223ad36d4436ed3eeb843041b66ac21dcee34",
+			"revisionTime": "2019-01-06T03:45:47Z"
 		},
 		{
 			"checksumSHA1": "9TPZ7plxFmlYtMEv2LLXRCEQg7c=",