diff --git a/core/api.go b/core/api.go
index dab0709..e2c0b95 100644
--- a/core/api.go
+++ b/core/api.go
@@ -2,9 +2,7 @@ package core
 
 import (
 	"bytes"
-	"crypto/md5"
 	"encoding/binary"
-	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -109,10 +107,6 @@ var seq = uint32(0)
 
 func (caller apiCaller) uploadAPI(w http.ResponseWriter, r *http.Request) error {
 	if r.Method == "PUT" {
-		hasher := md5.New()
-		hasher.Write(caller.mg.service().serviceCodeBytes)
-		subfolder := hex.EncodeToString(hasher.Sum(nil))[:8]
-
 		infile, header, err := r.FormFile("file")
 		if err != nil {
 			w.WriteHeader(http.StatusBadRequest)
@@ -128,17 +122,16 @@ func (caller apiCaller) uploadAPI(w http.ResponseWriter, r *http.Request) error
 		var b [5]byte
 		binary.BigEndian.PutUint32(b[0:4], uint32(time.Now().Unix()))
 		b[4] = byte(atomic.AddUint32(&seq, 1) % 255)
-		rf := hex.EncodeToString(b[1:])
-		newidstr := subfolder + rf
-		newidbt, _ := hex.DecodeString(newidstr)
-		newidobj := primitive.NewObjectID()
-		copy(newidobj[:], newidbt[:8])
 
+		newidobj := primitive.NewObjectID()
+		copy(newidobj[:], b[1:])
+
+		rf := newidobj.Hex()
 		var link string
 		if extract {
-			link = path.Join("static", subfolder, rf)
+			link = path.Join("static", rf)
 		} else {
-			link = path.Join("static", subfolder, rf, header.Filename)
+			link = path.Join("static", rf, header.Filename)
 		}
 
 		newdoc := FileDocumentDesc{