diff --git a/signer/core/apitypes/types.go b/signer/core/apitypes/types.go
index 19323246a7..81b7f8c80e 100644
--- a/signer/core/apitypes/types.go
+++ b/signer/core/apitypes/types.go
@@ -259,7 +259,6 @@ func (args *SendTxArgs) validateTxSidecar() error {
 	if args.Commitments == nil {
 		// Generate commitment and proof.
 		commitments := make([]kzg4844.Commitment, n)
-		proofs := make([]kzg4844.Proof, 0, n)
 		for i, b := range args.Blobs {
 			c, err := kzg4844.BlobToCommitment(&b)
 			if err != nil {
@@ -267,7 +266,9 @@ func (args *SendTxArgs) validateTxSidecar() error {
 			}
 			commitments[i] = c
 		}
-		if args.BlobVersion == 1 {
+		var proofs []kzg4844.Proof
+		if args.BlobVersion == types.BlobSidecarVersion1 {
+			proofs = make([]kzg4844.Proof, 0, n*kzg4844.CellProofsPerBlob)
 			for i, b := range args.Blobs {
 				p, err := kzg4844.ComputeCellProofs(&b)
 				if err != nil {
@@ -276,6 +277,7 @@ func (args *SendTxArgs) validateTxSidecar() error {
 				proofs = append(proofs, p...)
 			}
 		} else {
+			proofs = make([]kzg4844.Proof, 0, n)
 			for i, b := range args.Blobs {
 				p, err := kzg4844.ComputeBlobProof(&b, commitments[i])
 				if err != nil {
diff --git a/signer/core/apitypes/types_test.go b/signer/core/apitypes/types_test.go
index 3e8f3bd43b..f010cef207 100644
--- a/signer/core/apitypes/types_test.go
+++ b/signer/core/apitypes/types_test.go
@@ -20,7 +20,6 @@ import (
 	"crypto/rand"
 	"crypto/sha256"
 	"encoding/json"
-	"fmt"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -308,7 +307,7 @@ func TestValidateTxSidecar(t *testing.T) {
 			name: "blobs with v1 version flag - should generate cell proofs",
 			args: SendTxArgs{
 				Blobs:       []kzg4844.Blob{blob1},
-				BlobVersion: 1,
+				BlobVersion: types.BlobSidecarVersion1,
 			},
 			wantErr: false,
 		},
@@ -366,6 +365,17 @@ func TestValidateTxSidecar(t *testing.T) {
 			},
 			wantErr: true,
 		},
+		{
+			name: "invalid proof",
+			args: SendTxArgs{
+				BlobVersion: types.BlobSidecarVersion1,
+				Blobs:       []kzg4844.Blob{blob1},
+				Commitments: []kzg4844.Commitment{commitment1},
+				Proofs:      []kzg4844.Proof{proof1, proof2}, // wrong proof
+				BlobHashes:  []common.Hash{hash1},
+			},
+			wantErr: true,
+		},
 	}
 
 	for _, tt := range tests {
@@ -390,7 +400,6 @@ func TestValidateTxSidecar(t *testing.T) {
 						t.Errorf("validateTxSidecar() should have generated commitments")
 					}
 					if args.Proofs == nil || (len(args.Proofs) != len(args.Blobs) && len(args.Proofs) != len(args.Blobs)*kzg4844.CellProofsPerBlob) {
-						fmt.Println("proofs", args.Proofs)
 						t.Errorf("validateTxSidecar() should have generated proofs")
 					}
 					if args.BlobHashes == nil || len(args.BlobHashes) != len(args.Blobs) {