diff --git a/cmd/pmoxs3backuproxy/main.go b/cmd/pmoxs3backuproxy/main.go
index 2e7c4c2..5e122d9 100644
--- a/cmd/pmoxs3backuproxy/main.go
+++ b/cmd/pmoxs3backuproxy/main.go
@@ -309,17 +309,16 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 				}
 				w.Header().Add("Content-Length", fmt.Sprintf("%d", s.Size))
 				w.WriteHeader(http.StatusOK)
-
 				io.Copy(w, obj)
 				return
 			}
 		}
 
 		s3backuplog.WarnPrint("File %s not found in snapshot %s (%s)", r.URL.Query().Get("archive-name"), mostRecent.S3Prefix(), mostRecent.Files)
-
 		w.WriteHeader(http.StatusNotFound)
 		return
 	}
+
 	if strings.HasPrefix(r.RequestURI, "/fixed_index?") && s.H2Ticket != nil && r.Method == "POST" {
 		fidxname := r.URL.Query().Get("archive-name")
 		reusecsum := r.URL.Query().Get("reuse-csum")
@@ -485,6 +484,8 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		wid, _ := strconv.ParseInt(r.URL.Query().Get("wid"), 10, 32)
 		s3name := fmt.Sprintf("chunks/%s/%s/%s", digest[0:2], digest[2:4], digest[4:])
 
+		var known bool = false
+
 		objectStat, e := s.H2Ticket.Client.StatObject(
 			context.Background(),
 			*s.SelectedDataStore,
@@ -493,7 +494,8 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		)
 		if e != nil {
 			errResponse := minio.ToErrorResponse(e)
-			if errResponse.Code == "NoSuchKey" {
+			switch errResponse.Code {
+			case "NoSuchKey":
 				_, err := s.H2Ticket.Client.PutObject(
 					context.Background(),
 					*s.SelectedDataStore,
@@ -507,14 +509,29 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 					w.WriteHeader(http.StatusInternalServerError)
 					w.Write([]byte(err.Error()))
 				}
+			default:
+				s3backuplog.WarnPrint("Unhandled response checking for existant object: %s", errResponse.Code)
 			}
 		} else {
 			s3backuplog.DebugPrint("%s already in S3", objectStat.Key)
+			io.ReadAll(r.Body) // we must read data from stream, otherwise backup client gets out of sync
+			known = true
 		}
 		if s.Writers[int32(wid)].Chunksize == 0 {
 			//Here chunk size is derived
 			s.Writers[int32(wid)].Chunksize = uint64(size)
 		}
+		info := ChunkUploadInfo{}
+		info.Digest = digest
+		info.Offset = 0 // todo
+		info.Size = int64(size)
+		info.Known = known
+
+		r := Response{Data: info}
+		responsedata, _ := json.Marshal(r)
+		w.WriteHeader(http.StatusOK)
+		w.Header().Add("Content-Type", "application/json")
+		w.Write(responsedata)
 	}
 
 	if strings.HasPrefix(r.RequestURI, "/blob?") && s.H2Ticket != nil {
@@ -558,9 +575,7 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 		w.Header().Add("Content-Length", fmt.Sprintf("%d", st.Size))
 		w.WriteHeader(http.StatusOK)
-
 		io.Copy(w, obj)
-
 	}
 
 	if strings.HasPrefix(r.RequestURI, "/chunk?") && s.H2Ticket != nil {
diff --git a/cmd/pmoxs3backuproxy/types.go b/cmd/pmoxs3backuproxy/types.go
index ddf9b3f..241a17a 100644
--- a/cmd/pmoxs3backuproxy/types.go
+++ b/cmd/pmoxs3backuproxy/types.go
@@ -74,6 +74,13 @@ type FixedIndexCloseRequest struct {
 	Size       int64  `json:"size"`
 }
 
+type ChunkUploadInfo struct {
+	Digest string `json:"digest"`
+	Offset int64  `json:"offset"`
+	Size   int64  `json:"size"`
+	Known  bool   `json:"chunk_is_known"`
+}
+
 type Response struct {
 	Data interface{} `json:"data"`
 	// other fields