diff --git a/internal/util.go b/internal/util.go
index 59fe5a2..81acff8 100644
--- a/internal/util.go
+++ b/internal/util.go
@@ -48,7 +48,19 @@ func ReadLegacyTrieNode(db ethdb.KeyValueReader, hash common.Hash, codec uint64)
 	return enc, nil
 }
 
-func WriteLegacyTrieNode(db ethdb.KeyValueWriter, hash common.Hash, codec uint64, data []byte) error {
+// HasLegacyTrieNode checks if the trie node with the provided hash is present in db.
+func HasLegacyTrieNode(db ethdb.KeyValueReader, hash common.Hash, codec uint64) bool {
+	cid, err := Keccak256ToCid(codec, hash[:])
+	if err != nil {
+		return false
+	}
+	ok, _ := db.Has(cid.Bytes())
+	return ok
+}
+
+func WriteLegacyTrieNode(db ethdb.KeyValueWriter, hash common.Hash, data []byte, codec uint64) error {
+	//
+	panic("Writing to the DB is disabled")
 	cid, err := Keccak256ToCid(codec, hash[:])
 	if err != nil {
 		return err
@@ -61,5 +73,5 @@ func ReadCode(db ethdb.KeyValueReader, hash common.Hash) ([]byte, error) {
 }
 
 func WriteCode(db ethdb.KeyValueWriter, hash common.Hash, code []byte) error {
-	return WriteLegacyTrieNode(db, hash, ipld.RawBinary, code)
+	return WriteLegacyTrieNode(db, hash, code, ipld.RawBinary)
 }
diff --git a/trie_by_cid/doc.go b/trie_by_cid/doc.go
index 4b9b440..e615661 100644
--- a/trie_by_cid/doc.go
+++ b/trie_by_cid/doc.go
@@ -1,3 +1,15 @@
 // This package is a near complete copy of go-ethereum/trie and go-ethereum/core/state, modified to use
 // a v0 IPFS blockstore as the backing DB, i.e. DB values are indexed by CID rather than hash.
 package trie_by_cid
+
+// Note: This is written so as to minimize the difference from the geth packages to allow easier
+// patching during upgrades.
+//
+// Changes to the original functionality should be marked with (ipld-eth-statedb change)
+// The main changes are within the triedb/hashdb package.
+//
+// Writes are currently disabled and will panic, but they may be useful for testing if possible.
+//
+// Tests from the original source are preserved as much as reasonably possible.  Memory DBs are
+// replaced with Postgres connections within the state package, but not the trie packages, since
+// they mostly check the structural consistency of the trie.
diff --git a/trie_by_cid/state/statedb.go b/trie_by_cid/state/statedb.go
index e70f17c..53eed75 100644
--- a/trie_by_cid/state/statedb.go
+++ b/trie_by_cid/state/statedb.go
@@ -32,6 +32,7 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/holiman/uint256"
 
+	"github.com/cerc-io/ipld-eth-statedb/internal"
 	"github.com/cerc-io/ipld-eth-statedb/trie_by_cid/trie"
 	"github.com/cerc-io/ipld-eth-statedb/trie_by_cid/trie/trienode"
 	"github.com/cerc-io/ipld-eth-statedb/trie_by_cid/trie/triestate"
@@ -1192,7 +1193,8 @@ func (s *StateDB) Commit(block uint64, deleteEmptyObjects bool) (common.Hash, er
 		}
 		// Write any contract code associated with the state object
 		if obj.code != nil && obj.dirtyCode {
-			rawdb.WriteCode(codeWriter, common.BytesToHash(obj.CodeHash()), obj.code)
+			// Writes are currently disabled and this will panic (ipld-eth-statedb change)
+			internal.WriteCode(codeWriter, common.BytesToHash(obj.CodeHash()), obj.code)
 			obj.dirtyCode = false
 		}
 		// Write any storage changes in the state object to its storage trie
diff --git a/trie_by_cid/triedb/database.go b/trie_by_cid/triedb/database.go
index fc3a519..1cbc345 100644
--- a/trie_by_cid/triedb/database.go
+++ b/trie_by_cid/triedb/database.go
@@ -109,7 +109,8 @@ func NewDatabase(diskdb ethdb.Database, config *Config) *Database {
 		log.Crit("Both 'hash' and 'path' mode are configured")
 	}
 	if config.PathDB != nil {
-		db.backend = pathdb.New(diskdb, config.PathDB)
+		// Disable PathDB (ipld-eth-statedb change). TODO: look into implementing it
+		panic("PathDB is not compatible with ipld-eth-statedb")
 	} else {
 		var resolver hashdb.ChildResolver
 		if config.IsVerkle {
diff --git a/trie_by_cid/triedb/hashdb/database.go b/trie_by_cid/triedb/hashdb/database.go
index 68f539f..e63fbd1 100644
--- a/trie_by_cid/triedb/hashdb/database.go
+++ b/trie_by_cid/triedb/hashdb/database.go
@@ -359,7 +359,7 @@ func (db *Database) Cap(limit common.StorageSize) error {
 	for size > limit && oldest != (common.Hash{}) {
 		// Fetch the oldest referenced node and push into the batch
 		node := db.dirties[oldest]
-		rawdb.WriteLegacyTrieNode(batch, oldest, node.node)
+		internal.WriteLegacyTrieNode(batch, oldest, node.node, 0)
 
 		// If we exceeded the ideal batch size, commit and reset
 		if batch.ValueSize() >= ethdb.IdealBatchSize {
@@ -482,7 +482,9 @@ func (db *Database) commit(hash common.Hash, batch ethdb.Batch, uncacher *cleane
 		return err
 	}
 	// If we've reached an optimal batch size, commit and start over
-	rawdb.WriteLegacyTrieNode(batch, hash, node.node)
+	// FIXME: placeholder - this won't work unless we know the codec we need here,
+	// so writes are currently disabled and this will panic (ipld-eth-statedb change)
+	internal.WriteLegacyTrieNode(batch, hash, node.node, 0)
 	if batch.ValueSize() >= ethdb.IdealBatchSize {
 		if err := batch.Write(); err != nil {
 			return err
@@ -552,7 +554,7 @@ func (c *cleaner) Delete(key []byte) error {
 // Initialized returns an indicator if state data is already initialized
 // in hash-based scheme by checking the presence of genesis state.
 func (db *Database) Initialized(genesisRoot common.Hash) bool {
-	return rawdb.HasLegacyTrieNode(db.diskdb, genesisRoot)
+	return internal.HasLegacyTrieNode(db.diskdb, genesisRoot, internal.StateTrieCodec)
 }
 
 // Update inserts the dirty nodes in provided nodeset into database and link the