diff --git a/metadata/directory.go b/metadata/directory.go
index 9b251a1..867f945 100644
--- a/metadata/directory.go
+++ b/metadata/directory.go
@@ -7,15 +7,19 @@ import (
 	"github.com/vmihailenco/msgpack/v5"
 )
 
+type directoryReferenceMap map[string]DirectoryReference
+type fileReferenceMap map[string]FileReference
+
 type DirectoryMetadata struct {
-	Details       DirectoryMetadataDetails      `json:"details"`
-	Directories   map[string]DirectoryReference `json:"directories"`
-	Files         map[string]FileReference      `json:"files"`
-	ExtraMetadata ExtraMetadata                 `json:"extraMetadata"`
+	Details       DirectoryMetadataDetails `json:"details"`
+	Directories   directoryReferenceMap    `json:"directories"`
+	Files         fileReferenceMap         `json:"files"`
+	ExtraMetadata ExtraMetadata            `json:"extraMetadata"`
 	BaseMetadata
 }
 
 var _ SerializableMetadata = (*DirectoryMetadata)(nil)
+var _ SerializableMetadata = (*directoryReferenceMap)(nil)
 
 func NewDirectoryMetadata(details DirectoryMetadataDetails, directories map[string]DirectoryReference, files map[string]FileReference, extraMetadata ExtraMetadata) *DirectoryMetadata {
 	dirMetadata := &DirectoryMetadata{
@@ -90,3 +94,96 @@ func (dm *DirectoryMetadata) DecodeMsgpack(dec *msgpack.Decoder) error {
 
 	return nil
 }
+func (drm directoryReferenceMap) EncodeMsgpack(enc *msgpack.Encoder) error {
+	// First, encode the length of the map
+	if err := enc.EncodeMapLen(len(drm)); err != nil {
+		return err
+	}
+
+	// Then, encode each key-value pair
+	for k, v := range drm {
+		if err := enc.EncodeString(k); err != nil {
+			return err
+		}
+		if err := enc.Encode(&v); err != nil { // Assuming DirectoryReference can be encoded by msgpack
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (drm *directoryReferenceMap) DecodeMsgpack(dec *msgpack.Decoder) error {
+	// Read the map length
+	l, err := dec.DecodeMapLen()
+	if err != nil {
+		return err
+	}
+
+	// Initialize the map if it's nil
+	if *drm == nil {
+		*drm = make(directoryReferenceMap, l)
+	}
+
+	// Decode each key-value pair
+	for i := 0; i < l; i++ {
+		key, err := dec.DecodeString()
+		if err != nil {
+			return err
+		}
+		var value DirectoryReference
+		if err := dec.Decode(&value); err != nil {
+			return err
+		}
+		(*drm)[key] = value
+	}
+
+	return nil
+}
+
+func (frm fileReferenceMap) EncodeMsgpack(enc *msgpack.Encoder) error {
+	// First, encode the length of the map
+	if err := enc.EncodeMapLen(len(frm)); err != nil {
+		return err
+	}
+
+	// Then, encode each key-value pair
+	for k, v := range frm {
+		if err := enc.EncodeString(k); err != nil {
+			return err
+		}
+		if err := enc.Encode(&v); err != nil { // Assuming DirectoryReference can be encoded by msgpack
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (drm *fileReferenceMap) DecodeMsgpack(dec *msgpack.Decoder) error {
+	// Read the map length
+	l, err := dec.DecodeMapLen()
+	if err != nil {
+		return err
+	}
+
+	// Initialize the map if it's nil
+	if *drm == nil {
+		*drm = make(fileReferenceMap, l)
+	}
+
+	// Decode each key-value pair
+	for i := 0; i < l; i++ {
+		key, err := dec.DecodeString()
+		if err != nil {
+			return err
+		}
+		var value FileReference
+		if err := dec.Decode(&value); err != nil {
+			return err
+		}
+		(*drm)[key] = value
+	}
+
+	return nil
+}