diff --git a/claim/claim.go b/claim/claim.go
index 13f294f..f663cc4 100644
--- a/claim/claim.go
+++ b/claim/claim.go
@@ -31,6 +31,7 @@ type ClaimHelper struct {
 	ClaimID     []byte
 	Version     version
 	Signature   []byte
+	Payload     []byte
 }
 
 const migrationErrorMessage = "migration from v1 to v2 protobuf failed with: "
@@ -143,6 +144,7 @@ func (c *ClaimHelper) LoadFromBytes(raw_claim []byte, blockchainName string) err
 		ClaimID:     claimID,
 		Version:     version,
 		Signature:   signature,
+		Payload:     pbPayload,
 	}
 
 	err = c.ValidateAddresses(blockchainName)
@@ -166,7 +168,7 @@ func (c *ClaimHelper) LoadFromHexString(claim_hex string, blockchainName string)
 }
 
 func DecodeClaimProtoBytes(serialized []byte, blockchainName string) (*ClaimHelper, error) {
-	claim := &ClaimHelper{&pb.Claim{}, nil, nil, NoSig, nil}
+	claim := &ClaimHelper{&pb.Claim{}, nil, nil, NoSig, nil, nil}
 	err := claim.LoadFromBytes(serialized, blockchainName)
 	if err != nil {
 		return nil, err
diff --git a/claim/serialization.go b/claim/serialization.go
index 8922d51..43d38d6 100644
--- a/claim/serialization.go
+++ b/claim/serialization.go
@@ -25,14 +25,13 @@ func (c *ClaimHelper) serialized() ([]byte, error) {
 
 func (c *ClaimHelper) getProtobuf() *pb.Claim {
 	claim := &pb.Claim{
-		Title:       c.Title,
-		Description: c.Description,
-		Thumbnail:   c.Thumbnail,
-		Tags:        c.Tags,
-		Languages:   c.Languages,
-		Locations:   c.Locations,
+		Title:       c.GetTitle(),
+		Description: c.GetDescription(),
+		Thumbnail:   c.GetThumbnail(),
+		Tags:        c.GetTags(),
+		Languages:   c.GetLanguages(),
+		Locations:   c.GetLocations(),
 	}
-	return c.Claim
 	if c.GetChannel() != nil {
 		claim.Type = &pb.Claim_Channel{Channel: c.GetChannel()}
 	} else if c.GetStream() != nil {
diff --git a/claim/sign_test.go b/claim/sign_test.go
index 314179c..e813f07 100644
--- a/claim/sign_test.go
+++ b/claim/sign_test.go
@@ -14,7 +14,7 @@ func TestSign(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	channel := &ClaimHelper{newChannelClaim(), nil, nil, NoSig, nil}
+	channel := &ClaimHelper{newChannelClaim(), nil, nil, NoSig, nil, nil}
 	pubkeyBytes, err := PublicKeyToDER(privateKey.PubKey())
 	if err != nil {
 		t.Error(err)
@@ -29,7 +29,7 @@ func TestSign(t *testing.T) {
 		return
 	}
 
-	claim := &ClaimHelper{newStreamClaim(), nil, reverseBytes(claimIDHexBytes), WithSig, nil}
+	claim := &ClaimHelper{newStreamClaim(), nil, reverseBytes(claimIDHexBytes), WithSig, nil, nil}
 	claim.Claim.Title = "Test title"
 	claim.Claim.Description = "Test description"
 	sig, err := Sign(*privateKey, *channel, *claim, txid)
@@ -104,7 +104,7 @@ func TestSignWithV1Channel(t *testing.T) {
 		return
 	}
 
-	claim := &ClaimHelper{newStreamClaim(), nil, reverseBytes(claimIDHexBytes), WithSig, nil}
+	claim := &ClaimHelper{newStreamClaim(), nil, reverseBytes(claimIDHexBytes), WithSig, nil, nil}
 	claim.Claim.Title = "Test title"
 	claim.Claim.Description = "Test description"
 	sig, err := Sign(*privateKey, *channel, *claim, txid)
diff --git a/claim/validator.go b/claim/validator.go
index 4edac28..4c243af 100644
--- a/claim/validator.go
+++ b/claim/validator.go
@@ -5,6 +5,7 @@ import (
 	"crypto/sha256"
 	"crypto/x509/pkix"
 	"encoding/asn1"
+	"encoding/binary"
 	"encoding/hex"
 	"math/big"
 
@@ -57,13 +58,13 @@ func (c *ClaimHelper) ValidateClaimSignature(certificate *ClaimHelper, k string,
 	return c.validateClaimSignature(certificate, k, certificateId, blockchainName)
 }
 
-func (c *ClaimHelper) validateClaimSignature(certificate *ClaimHelper, firstInputTxID, certificateId string, blockchainName string) (bool, error) {
+func (c *ClaimHelper) validateClaimSignature(certificate *ClaimHelper, firstInputTxHash, certificateId string, blockchainName string) (bool, error) {
 	certificateIdSlice, err := hex.DecodeString(certificateId)
 	if err != nil {
 		return false, errors.Err(err)
 	}
 	certificateIdSlice = reverseBytes(certificateIdSlice)
-	firstInputTxIDBytes, err := hex.DecodeString(firstInputTxID)
+	firstInputTxIDBytes, err := hex.DecodeString(firstInputTxHash)
 	if err != nil {
 		return false, errors.Err(err)
 	}
@@ -77,12 +78,7 @@ func (c *ClaimHelper) validateClaimSignature(certificate *ClaimHelper, firstInpu
 		signatureBytes[i] = b
 	}
 
-	serialized, err := c.serialized()
-	if err != nil {
-		return false, errors.Err("serialization error")
-	}
-
-	claimDigest := getClaimSignatureDigest(firstInputTxIDBytes, certificateIdSlice, serialized)
+	claimDigest := getClaimSignatureDigest(firstInputTxIDBytes, certificateIdSlice, c.Payload)
 	return c.VerifyDigest(certificate, signatureBytes, claimDigest), nil
 }
 
@@ -120,3 +116,13 @@ func (c *ClaimHelper) validateV1ClaimSignature(certificate *ClaimHelper, claimAd
 	claimDigest := getClaimSignatureDigest(claimAddress[:], serializedNoSig, certificateIdSlice)
 	return c.VerifyDigest(certificate, signatureBytes, claimDigest), nil
 }
+
+func GetOutpointHash(txid string, vout uint32) (string, error) {
+	txidBytes, err := hex.DecodeString(txid)
+	if err != nil {
+		return "", errors.Err(err)
+	}
+	var voutBytes = make([]byte, 4)
+	binary.LittleEndian.PutUint32(voutBytes, vout)
+	return hex.EncodeToString(append(reverseBytes(txidBytes), voutBytes...)), nil
+}
diff --git a/claim/validator_test.go b/claim/validator_test.go
index eca3ba6..ef88a4d 100644
--- a/claim/validator_test.go
+++ b/claim/validator_test.go
@@ -2,6 +2,8 @@ package claim
 
 import (
 	"testing"
+
+	"gotest.tools/assert"
 )
 
 func TestV1ValidateClaimSignature(t *testing.T) {
@@ -53,3 +55,40 @@ func TestV1FailToValidateClaimSignature(t *testing.T) {
 		t.Error("failed to validate signature:", result)
 	}
 }
+
+func TestV2ValidateClaimSignature(t *testing.T) {
+	cert_claim_hex := "00125a0a583056301006072a8648ce3d020106052b8104000a034200045a0343c155302280da01ae0001b7295241eb03c42a837acf92ccb9680892f7db50fd1d3c14b28bb594e304f05fc4ae7c1f222a85d1d1a3461b3cfb9906f66cb5"
+	signed_claim_hex := "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"
+
+	signed_claim, err := DecodeClaimHex(signed_claim_hex, "lbrycrd_main")
+	if err != nil {
+		t.Error(err)
+	}
+	cert_claim, err := DecodeClaimHex(cert_claim_hex, "lbrycrd_main")
+	if err != nil {
+		t.Error(err)
+	}
+
+	firstInputTxHash, err := GetOutpointHash("becb96a4a2e66bd24f083772fe9da904654ea9b5f07cc5bfbee233355911ddb1", uint32(0))
+	if err != nil {
+		t.Error(err)
+	}
+	cert_id := "e67323a67a42307410f9679bf7fb344a428eb75c"
+
+	result, err := signed_claim.ValidateClaimSignature(cert_claim, firstInputTxHash, cert_id, "lbrycrd_main")
+	if err != nil {
+		t.Error(err)
+	}
+	if result != true {
+		t.Error("failed to validate signature:", result)
+	}
+
+}
+
+func TestGetOutpointHash(t *testing.T) {
+	hash, err := GetOutpointHash("dc3dcf2f94d3c91e454ac2474802e20f26b30705372dda43890c811d918aef64", 1)
+	if err != nil {
+		t.Error(err)
+	}
+	assert.Assert(t, hash == "64ef8a911d810c8943da2d370507b3260fe2024847c24a451ec9d3942fcf3ddc01000000", uint(1))
+}