diff --git a/metadata/directory_map.go b/metadata/directory_map.go
index 09cd176..16528d0 100644
--- a/metadata/directory_map.go
+++ b/metadata/directory_map.go
@@ -18,11 +18,20 @@ type directoryReferenceSerializationMap struct {
 	linkedhashmap.Map
 }
 
+type fileVersionSerializationMap struct {
+	linkedhashmap.Map
+}
+
+type fileVersionThumbnailSerializationMap struct {
+	linkedhashmap.Map
+}
+
 type unmarshalNewInstanceFunc func() interface{}
 
 var _ SerializableMetadata = (*directoryReferenceMap)(nil)
 var _ SerializableMetadata = (*fileReferenceMap)(nil)
 var _ msgpack.CustomEncoder = (*directoryReferenceSerializationMap)(nil)
+var _ msgpack.CustomEncoder = (*fileVersionSerializationMap)(nil)
 
 func unmarshalMapMsgpack(dec *msgpack.Decoder, m *linkedhashmap.Map, placeholder interface{}, intMap bool) error {
 	*m = *linkedhashmap.New()
@@ -200,3 +209,10 @@ func (drm *directoryReferenceMap) UnmarshalJSON(bytes []byte) error {
 func (frm directoryReferenceSerializationMap) EncodeMsgpack(enc *msgpack.Encoder) error {
 	return marshallMapMsgpack(enc, &frm.Map)
 }
+
+func (fvs fileVersionSerializationMap) EncodeMsgpack(enc *msgpack.Encoder) error {
+	return marshallMapMsgpack(enc, &fvs.Map)
+}
+func (fvts fileVersionThumbnailSerializationMap) EncodeMsgpack(enc *msgpack.Encoder) error {
+	return marshallMapMsgpack(enc, &fvts.Map)
+}
diff --git a/metadata/file_version.go b/metadata/file_version.go
index 7cbf11f..4ea2015 100644
--- a/metadata/file_version.go
+++ b/metadata/file_version.go
@@ -2,6 +2,7 @@ package metadata
 
 import (
 	"git.lumeweb.com/LumeWeb/libs5-go/encoding"
+	"github.com/emirpasic/gods/maps/linkedhashmap"
 	"github.com/vmihailenco/msgpack/v5"
 )
 
@@ -26,16 +27,17 @@ func NewFileVersion(ts int, encryptedCID *encoding.EncryptedCID, plaintextCID *e
 }
 
 func (fv *FileVersion) EncodeMsgpack(enc *msgpack.Encoder) error {
-	data := map[int]interface{}{
-		8: fv.Ts,
-	}
+
+	fmap := &fileVersionSerializationMap{*linkedhashmap.New()}
+
+	fmap.Put(8, fv.Ts)
 
 	if fv.EncryptedCID != nil {
-		data[1] = fv.EncryptedCID
+		fmap.Put(1, fv.EncryptedCID)
 	}
 
 	if fv.PlaintextCID != nil {
-		data[2] = fv.PlaintextCID
+		fmap.Put(2, fv.PlaintextCID)
 	}
 
 	if len(fv.Hashes) > 0 {
@@ -43,14 +45,14 @@ func (fv *FileVersion) EncodeMsgpack(enc *msgpack.Encoder) error {
 		for i, hash := range fv.Hashes {
 			hashesData[i] = hash.FullBytes
 		}
-		data[9] = hashesData
+		fmap.Put(9, hashesData)
 	}
 
 	if fv.Thumbnail != nil {
-		data[10] = fv.Thumbnail
+		fmap.Put(10, fv.Thumbnail)
 	}
 
-	return enc.Encode(data)
+	return enc.Encode(fmap)
 }
 
 func (fv *FileVersion) DecodeMsgpack(dec *msgpack.Decoder) error {
diff --git a/metadata/file_version_thumbnail.go b/metadata/file_version_thumbnail.go
index 33cc6ba..7d6dee2 100644
--- a/metadata/file_version_thumbnail.go
+++ b/metadata/file_version_thumbnail.go
@@ -2,6 +2,7 @@ package metadata
 
 import (
 	"git.lumeweb.com/LumeWeb/libs5-go/encoding"
+	"github.com/emirpasic/gods/maps/linkedhashmap"
 	"github.com/vmihailenco/msgpack/v5"
 )
 
@@ -22,20 +23,20 @@ func NewFileVersionThumbnail(imageType string, aspectRatio float64, cid *encodin
 }
 
 func (fvt *FileVersionThumbnail) EncodeMsgpack(enc *msgpack.Encoder) error {
-	data := map[int]interface{}{
-		2: fvt.AspectRatio,
-		3: fvt.CID.ToBytes(),
-	}
+	fmap := &fileVersionThumbnailSerializationMap{*linkedhashmap.New()}
+
+	fmap.Put(2, fvt.AspectRatio)
+	fmap.Put(3, fvt.CID.ToBytes())
 
 	if fvt.ImageType != "" {
-		data[1] = fvt.ImageType
+		fmap.Put(1, fvt.ImageType)
 	}
 
 	if fvt.Thumbhash != nil {
-		data[4] = fvt.Thumbhash
+		fmap.Put(4, fvt.Thumbhash)
 	}
 
-	return enc.Encode(data)
+	return enc.Encode(fmap)
 }
 func (fvt *FileVersionThumbnail) DecodeMsgpack(dec *msgpack.Decoder) error {
 	mapLen, err := dec.DecodeMapLen()