diff --git a/indexer/meta_data.go b/indexer/meta_data.go
index aa30d646..b74cddaa 100644
--- a/indexer/meta_data.go
+++ b/indexer/meta_data.go
@@ -9,6 +9,13 @@ import (
 	"github.com/ozontech/seq-db/tokenizer"
 )
 
+const (
+	metaDataVersion1 uint16 = 1 // milliseconds MID support (no longer supported)
+	metaDataVersion2 uint16 = 2 // nanoseconds MID support
+
+	metaDataVersion = metaDataVersion2
+)
+
 type MetaData struct {
 	ID seq.ID
 	// Size of an uncompressed document in bytes.
@@ -35,8 +42,7 @@ func (m *MetaData) MarshalBinaryTo(b []byte) []byte {
 	b = binary.LittleEndian.AppendUint16(b, metadataMagic)
 
 	// Append current binary version of the metadata.
-	const version = 2
-	b = binary.LittleEndian.AppendUint16(b, version)
+	b = binary.LittleEndian.AppendUint16(b, metaDataVersion)
 
 	// Encode seq.ID.
 	b = binary.LittleEndian.AppendUint64(b, uint64(m.ID.MID))
@@ -65,29 +71,15 @@ func (m *MetaData) UnmarshalBinary(b []byte) error {
 	b = b[2:]
 
 	switch version {
-	case 1:
-		// Version 1 meta stores MID in milliseconds
-		return m.unmarshalVersion1(b)
-	case 2:
-		// Version 2 meta stores MID in nanoseconds
-		return m.unmarshalVersion2(b)
+	case metaDataVersion1:
+		return fmt.Errorf("version: %d no longer supported", version)
+	case metaDataVersion2:
+		return m.unmarshal(b)
 	default:
 		return fmt.Errorf("unimplemented metadata version: %d", version)
 	}
 }
 
-func (m *MetaData) unmarshalVersion1(b []byte) error {
-	if err := m.unmarshal(b); err != nil {
-		return err
-	}
-	m.ID.MID = seq.MillisToMID(uint64(m.ID.MID))
-	return nil
-}
-
-func (m *MetaData) unmarshalVersion2(b []byte) error {
-	return m.unmarshal(b)
-}
-
 func (m *MetaData) unmarshal(b []byte) error {
 	// Decode seq.ID.
 	m.ID.MID = seq.MID(binary.LittleEndian.Uint64(b))