diff --git a/core/stateless/database.go b/core/stateless/database.go
index f54c123dda..7b035527fc 100644
--- a/core/stateless/database.go
+++ b/core/stateless/database.go
@@ -44,9 +44,7 @@ func (w *Witness) MakeHashDB() ethdb.Database {
 		rawdb.WriteHeader(memdb, header)
 	}
 	// Inject all the bytecodes into the ephemeral database
-	for code := range w.Codes {
-		blob := []byte(code)
-
+	for _, blob := range w.Codes {
 		hasher.Reset()
 		hasher.Write(blob)
 		hasher.Read(hash)
@@ -54,9 +52,7 @@ func (w *Witness) MakeHashDB() ethdb.Database {
 		rawdb.WriteCode(memdb, common.BytesToHash(hash), blob)
 	}
 	// Inject all the MPT trie nodes into the ephemeral database
-	for node := range w.State {
-		blob := []byte(node)
-
+	for _, blob := range w.State {
 		hasher.Reset()
 		hasher.Write(blob)
 		hasher.Read(hash)
diff --git a/core/stateless/encoding.go b/core/stateless/encoding.go
index 5c43159e66..8aa98a0682 100644
--- a/core/stateless/encoding.go
+++ b/core/stateless/encoding.go
@@ -18,6 +18,7 @@ package stateless
 
 import (
 	"io"
+	"slices"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/types"
@@ -26,47 +27,21 @@ import (
 
 // ToExtWitness converts our internal witness representation to the consensus one.
 func (w *Witness) ToExtWitness() *ExtWitness {
-	ext := &ExtWitness{
-		Headers: w.Headers,
+	return &ExtWitness{
+		Headers: slices.Clone(w.Headers),
+		Codes:   slices.Clone(w.Codes),
+		State:   slices.Clone(w.State),
 	}
-	ext.Codes = make([]hexutil.Bytes, 0, len(w.Codes))
-	for code := range w.Codes {
-		ext.Codes = append(ext.Codes, []byte(code))
-	}
-	ext.State = make([]hexutil.Bytes, 0, len(w.State))
-	for node := range w.State {
-		ext.State = append(ext.State, []byte(node))
-	}
-	return ext
-}
-
-// fromExtWitness converts the consensus witness format into our internal one.
-func (w *Witness) fromExtWitness(ext *ExtWitness) error {
-	w.Headers = ext.Headers
-
-	w.Codes = make(map[string]struct{}, len(ext.Codes))
-	for _, code := range ext.Codes {
-		w.Codes[string(code)] = struct{}{}
-	}
-	w.State = make(map[string]struct{}, len(ext.State))
-	for _, node := range ext.State {
-		w.State[string(node)] = struct{}{}
-	}
-	return nil
 }
 
 // EncodeRLP serializes a witness as RLP.
 func (w *Witness) EncodeRLP(wr io.Writer) error {
-	return rlp.Encode(wr, w.ToExtWitness())
+	return rlp.Encode(wr, w)
 }
 
 // DecodeRLP decodes a witness from RLP.
 func (w *Witness) DecodeRLP(s *rlp.Stream) error {
-	var ext ExtWitness
-	if err := s.Decode(&ext); err != nil {
-		return err
-	}
-	return w.fromExtWitness(&ext)
+	return s.Decode(&w)
 }
 
 // ExtWitness is a witness RLP encoding for transferring across clients.
@@ -74,5 +49,4 @@ type ExtWitness struct {
 	Headers []*types.Header `json:"headers"`
 	Codes   []hexutil.Bytes `json:"codes"`
 	State   []hexutil.Bytes `json:"state"`
-	Keys    []hexutil.Bytes `json:"keys"`
 }
diff --git a/core/stateless/witness.go b/core/stateless/witness.go
index 588c895a2f..d85cd6f346 100644
--- a/core/stateless/witness.go
+++ b/core/stateless/witness.go
@@ -18,11 +18,11 @@ package stateless
 
 import (
 	"errors"
-	"maps"
 	"slices"
 	"sync"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/types"
 )
 
@@ -38,9 +38,9 @@ type HeaderReader interface {
 type Witness struct {
 	context *types.Header // Header to which this witness belongs to, with rootHash and receiptHash zeroed out
 
-	Headers []*types.Header     // Past headers in reverse order (0=parent, 1=parent's-parent, etc). First *must* be set.
-	Codes   map[string]struct{} // Set of bytecodes ran or accessed
-	State   map[string]struct{} // Set of MPT state trie nodes (account and storage together)
+	Headers []*types.Header `json:"headers"` // Past headers in reverse order (0=parent, 1=parent's-parent, etc). First *must* be set.
+	Codes   []hexutil.Bytes `json:"codes"`   // Set of bytecodes ran or accessed
+	State   []hexutil.Bytes `json:"state"`   // Set of MPT state trie nodes (account and storage together)
 
 	chain HeaderReader // Chain reader to convert block hash ops to header proofs
 	lock  sync.Mutex   // Lock to allow concurrent state insertions
@@ -62,8 +62,8 @@ func NewWitness(context *types.Header, chain HeaderReader) (*Witness, error) {
 	return &Witness{
 		context: context,
 		Headers: headers,
-		Codes:   make(map[string]struct{}),
-		State:   make(map[string]struct{}),
+		Codes:   []hexutil.Bytes{},
+		State:   []hexutil.Bytes{},
 		chain:   chain,
 	}, nil
 }
@@ -84,7 +84,7 @@ func (w *Witness) AddCode(code []byte) {
 	if len(code) == 0 {
 		return
 	}
-	w.Codes[string(code)] = struct{}{}
+	w.Codes = append(w.Codes, code)
 }
 
 // AddState inserts a batch of MPT trie nodes into the witness.
@@ -96,7 +96,7 @@ func (w *Witness) AddState(nodes map[string][]byte) {
 	defer w.lock.Unlock()
 
 	for _, value := range nodes {
-		w.State[string(value)] = struct{}{}
+		w.State = append(w.State, value)
 	}
 }
 
@@ -109,8 +109,8 @@ func (w *Witness) AddKey() {
 func (w *Witness) Copy() *Witness {
 	cpy := &Witness{
 		Headers: slices.Clone(w.Headers),
-		Codes:   maps.Clone(w.Codes),
-		State:   maps.Clone(w.State),
+		Codes:   slices.Clone(w.Codes),
+		State:   slices.Clone(w.State),
 		chain:   w.chain,
 	}
 	if w.context != nil {