diff --git a/beacon/engine/gen_ed.go b/beacon/engine/gen_ed.go
index 2a92e7420407..0ae5a3b8f1f1 100644
--- a/beacon/engine/gen_ed.go
+++ b/beacon/engine/gen_ed.go
@@ -34,7 +34,7 @@ func (e ExecutableData) MarshalJSON() ([]byte, error) {
 		Withdrawals      []*types.Withdrawal     `json:"withdrawals"`
 		BlobGasUsed      *hexutil.Uint64         `json:"blobGasUsed"`
 		ExcessBlobGas    *hexutil.Uint64         `json:"excessBlobGas"`
-		ExecutionWitness *types.ExecutionWitness `json:"executionWitness"`
+		ExecutionWitness *types.ExecutionWitness `json:"executionWitness,omitempty"`
 	}
 	var enc ExecutableData
 	enc.ParentHash = e.ParentHash
@@ -83,7 +83,7 @@ func (e *ExecutableData) UnmarshalJSON(input []byte) error {
 		Withdrawals      []*types.Withdrawal     `json:"withdrawals"`
 		BlobGasUsed      *hexutil.Uint64         `json:"blobGasUsed"`
 		ExcessBlobGas    *hexutil.Uint64         `json:"excessBlobGas"`
-		ExecutionWitness *types.ExecutionWitness `json:"executionWitness"`
+		ExecutionWitness *types.ExecutionWitness `json:"executionWitness,omitempty"`
 	}
 	var dec ExecutableData
 	if err := json.Unmarshal(input, &dec); err != nil {
diff --git a/core/types/gen_header_json.go b/core/types/gen_header_json.go
index bac475959dd9..806aeea9ec55 100644
--- a/core/types/gen_header_json.go
+++ b/core/types/gen_header_json.go
@@ -16,26 +16,27 @@ var _ = (*headerMarshaling)(nil)
 // MarshalJSON marshals as JSON.
 func (h Header) MarshalJSON() ([]byte, error) {
 	type Header struct {
-		ParentHash      common.Hash     `json:"parentHash"       gencodec:"required"`
-		UncleHash       common.Hash     `json:"sha3Uncles"       gencodec:"required"`
-		Coinbase        common.Address  `json:"miner"`
-		Root            common.Hash     `json:"stateRoot"        gencodec:"required"`
-		TxHash          common.Hash     `json:"transactionsRoot" gencodec:"required"`
-		ReceiptHash     common.Hash     `json:"receiptsRoot"     gencodec:"required"`
-		Bloom           Bloom           `json:"logsBloom"        gencodec:"required"`
-		Difficulty      *hexutil.Big    `json:"difficulty"       gencodec:"required"`
-		Number          *hexutil.Big    `json:"number"           gencodec:"required"`
-		GasLimit        hexutil.Uint64  `json:"gasLimit"         gencodec:"required"`
-		GasUsed         hexutil.Uint64  `json:"gasUsed"          gencodec:"required"`
-		Time            hexutil.Uint64  `json:"timestamp"        gencodec:"required"`
-		Extra           hexutil.Bytes   `json:"extraData"        gencodec:"required"`
-		MixDigest       common.Hash     `json:"mixHash"`
-		Nonce           BlockNonce      `json:"nonce"`
-		BaseFee         *hexutil.Big    `json:"baseFeePerGas" rlp:"optional"`
-		WithdrawalsHash *common.Hash    `json:"withdrawalsRoot" rlp:"optional"`
-		BlobGasUsed     *hexutil.Uint64 `json:"blobGasUsed" rlp:"optional"`
-		ExcessBlobGas   *hexutil.Uint64 `json:"excessBlobGas" rlp:"optional"`
-		Hash            common.Hash     `json:"hash"`
+		ParentHash       common.Hash       `json:"parentHash"       gencodec:"required"`
+		UncleHash        common.Hash       `json:"sha3Uncles"       gencodec:"required"`
+		Coinbase         common.Address    `json:"miner"`
+		Root             common.Hash       `json:"stateRoot"        gencodec:"required"`
+		TxHash           common.Hash       `json:"transactionsRoot" gencodec:"required"`
+		ReceiptHash      common.Hash       `json:"receiptsRoot"     gencodec:"required"`
+		Bloom            Bloom             `json:"logsBloom"        gencodec:"required"`
+		Difficulty       *hexutil.Big      `json:"difficulty"       gencodec:"required"`
+		Number           *hexutil.Big      `json:"number"           gencodec:"required"`
+		GasLimit         hexutil.Uint64    `json:"gasLimit"         gencodec:"required"`
+		GasUsed          hexutil.Uint64    `json:"gasUsed"          gencodec:"required"`
+		Time             hexutil.Uint64    `json:"timestamp"        gencodec:"required"`
+		Extra            hexutil.Bytes     `json:"extraData"        gencodec:"required"`
+		MixDigest        common.Hash       `json:"mixHash"`
+		Nonce            BlockNonce        `json:"nonce"`
+		BaseFee          *hexutil.Big      `json:"baseFeePerGas" rlp:"optional"`
+		WithdrawalsHash  *common.Hash      `json:"withdrawalsRoot" rlp:"optional"`
+		BlobGasUsed      *hexutil.Uint64   `json:"blobGasUsed" rlp:"optional"`
+		ExcessBlobGas    *hexutil.Uint64   `json:"excessBlobGas" rlp:"optional"`
+		ExecutionWitness *ExecutionWitness `json:"executionWitness" rlp:"-"`
+		Hash             common.Hash       `json:"hash"`
 	}
 	var enc Header
 	enc.ParentHash = h.ParentHash
@@ -57,6 +58,7 @@ func (h Header) MarshalJSON() ([]byte, error) {
 	enc.WithdrawalsHash = h.WithdrawalsHash
 	enc.BlobGasUsed = (*hexutil.Uint64)(h.BlobGasUsed)
 	enc.ExcessBlobGas = (*hexutil.Uint64)(h.ExcessBlobGas)
+	enc.ExecutionWitness = h.ExecutionWitness
 	enc.Hash = h.Hash()
 	return json.Marshal(&enc)
 }
@@ -64,25 +66,26 @@ func (h Header) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON unmarshals from JSON.
 func (h *Header) UnmarshalJSON(input []byte) error {
 	type Header struct {
-		ParentHash      *common.Hash    `json:"parentHash"       gencodec:"required"`
-		UncleHash       *common.Hash    `json:"sha3Uncles"       gencodec:"required"`
-		Coinbase        *common.Address `json:"miner"`
-		Root            *common.Hash    `json:"stateRoot"        gencodec:"required"`
-		TxHash          *common.Hash    `json:"transactionsRoot" gencodec:"required"`
-		ReceiptHash     *common.Hash    `json:"receiptsRoot"     gencodec:"required"`
-		Bloom           *Bloom          `json:"logsBloom"        gencodec:"required"`
-		Difficulty      *hexutil.Big    `json:"difficulty"       gencodec:"required"`
-		Number          *hexutil.Big    `json:"number"           gencodec:"required"`
-		GasLimit        *hexutil.Uint64 `json:"gasLimit"         gencodec:"required"`
-		GasUsed         *hexutil.Uint64 `json:"gasUsed"          gencodec:"required"`
-		Time            *hexutil.Uint64 `json:"timestamp"        gencodec:"required"`
-		Extra           *hexutil.Bytes  `json:"extraData"        gencodec:"required"`
-		MixDigest       *common.Hash    `json:"mixHash"`
-		Nonce           *BlockNonce     `json:"nonce"`
-		BaseFee         *hexutil.Big    `json:"baseFeePerGas" rlp:"optional"`
-		WithdrawalsHash *common.Hash    `json:"withdrawalsRoot" rlp:"optional"`
-		BlobGasUsed     *hexutil.Uint64 `json:"blobGasUsed" rlp:"optional"`
-		ExcessBlobGas   *hexutil.Uint64 `json:"excessBlobGas" rlp:"optional"`
+		ParentHash       *common.Hash      `json:"parentHash"       gencodec:"required"`
+		UncleHash        *common.Hash      `json:"sha3Uncles"       gencodec:"required"`
+		Coinbase         *common.Address   `json:"miner"`
+		Root             *common.Hash      `json:"stateRoot"        gencodec:"required"`
+		TxHash           *common.Hash      `json:"transactionsRoot" gencodec:"required"`
+		ReceiptHash      *common.Hash      `json:"receiptsRoot"     gencodec:"required"`
+		Bloom            *Bloom            `json:"logsBloom"        gencodec:"required"`
+		Difficulty       *hexutil.Big      `json:"difficulty"       gencodec:"required"`
+		Number           *hexutil.Big      `json:"number"           gencodec:"required"`
+		GasLimit         *hexutil.Uint64   `json:"gasLimit"         gencodec:"required"`
+		GasUsed          *hexutil.Uint64   `json:"gasUsed"          gencodec:"required"`
+		Time             *hexutil.Uint64   `json:"timestamp"        gencodec:"required"`
+		Extra            *hexutil.Bytes    `json:"extraData"        gencodec:"required"`
+		MixDigest        *common.Hash      `json:"mixHash"`
+		Nonce            *BlockNonce       `json:"nonce"`
+		BaseFee          *hexutil.Big      `json:"baseFeePerGas" rlp:"optional"`
+		WithdrawalsHash  *common.Hash      `json:"withdrawalsRoot" rlp:"optional"`
+		BlobGasUsed      *hexutil.Uint64   `json:"blobGasUsed" rlp:"optional"`
+		ExcessBlobGas    *hexutil.Uint64   `json:"excessBlobGas" rlp:"optional"`
+		ExecutionWitness *ExecutionWitness `json:"executionWitness" rlp:"-"`
 	}
 	var dec Header
 	if err := json.Unmarshal(input, &dec); err != nil {
@@ -157,5 +160,8 @@ func (h *Header) UnmarshalJSON(input []byte) error {
 	if dec.ExcessBlobGas != nil {
 		h.ExcessBlobGas = (*uint64)(dec.ExcessBlobGas)
 	}
+	if dec.ExecutionWitness != nil {
+		h.ExecutionWitness = dec.ExecutionWitness
+	}
 	return nil
 }