diff --git a/pkg/obiformats/json_writer.go b/pkg/obiformats/json_writer.go
index 2e5cf76..8f43b7d 100644
--- a/pkg/obiformats/json_writer.go
+++ b/pkg/obiformats/json_writer.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"strconv"
 	"strings"
+	"sync/atomic"
 	"time"
 
 	"github.com/goccy/go-json"
@@ -84,6 +85,7 @@ func FormatJSONBatch(batch obiiter.BioSequenceBatch) *bytes.Buffer {
 func WriteJSON(iterator obiiter.IBioSequence,
 	file io.WriteCloser,
 	options ...WithOption) (obiiter.IBioSequence, error) {
+	var latestChunk atomic.Int64
 
 	opt := MakeOptions(options)
 
@@ -97,6 +99,12 @@ func WriteJSON(iterator obiiter.IBioSequence,
 
 	go func() {
 		newIter.WaitAndClose()
+
+		chunkchan <- FileChunk{
+			Source: "end",
+			Raw:    bytes.NewBuffer([]byte("\n]\n")),
+			Order:  int(latestChunk.Load()) + 1,
+		}
 		for len(chunkchan) > 0 {
 			time.Sleep(time.Millisecond)
 		}
@@ -115,6 +123,7 @@ func WriteJSON(iterator obiiter.IBioSequence,
 			}
 
 			chunkchan <- ss
+			latestChunk.Store(int64(batch.Order()))
 			newIter.Push(batch)
 		}
 		newIter.Done()
diff --git a/pkg/obioptions/version.go b/pkg/obioptions/version.go
index a786cbe..b061222 100644
--- a/pkg/obioptions/version.go
+++ b/pkg/obioptions/version.go
@@ -7,7 +7,7 @@ import (
 // TODO: The version number is extracted from git. This induces that the version
 // corresponds to the last commit, and not the one when the file will be
 // commited
-var _Commit = "69ef175"
+var _Commit = "00b0edc"
 var _Version = "Release 4.2.0"
 
 // Version returns the version of the obitools package.
diff --git a/sample/AY189646 b/sample/AY189646
index 75be2b2..02146ff 100644
--- a/sample/AY189646
+++ b/sample/AY189646
@@ -1,4 +1,3 @@
-==> db_v05_idx_ori.fasta <==
 >AY189646 {"count":1,"obitag_ref_index":{"0":"9606@Homo sapiens@species","10":"9526@Catarrhini@parvorder","12":"1437010@Boreoeutheria@clade","16":"9347@Eutheria@clade","17":"40674@Mammalia@class","2":"207598@Homininae@subfamily","22":"117571@Euteleostomi@clade","25":"7776@Gnathostomata@clade","29":"33213@Bilateria@clade","3":"9604@Hominidae@family","30":"6072@Eumetazoa@clade","8":"314295@Hominoidea@superfamily"},"species_name":"Homo sapiens","taxid":9606} Homo sapiens clone arCan119 12S ribosomal RNA gene, partial sequence; mitochondrial gene for mitochondrial product.
 ttagccctaaacctcaacagttaaatcaacaaaactgctcgccagaacactacgrgccac
 agcttaaaactcaaaggacctggcggtgcttcatatccct
@@ -9,3 +8,5 @@ cagcttaaaactcaaaggacctggcggtgcttcatatccct
 ttagccctaaacttcaacagttaaattaacaaaactgctcgccagaacactacgagccac
 agcttaaaactcaaaggacctggcggtgcttcatatccct
 >AC008512 {"count":5,"obitag_ref_index":{"0":"9606@Homo sapiens@species","10":"1437010@Boreoeutheria@clade","14":"40674@Mammalia@class","18":"117571@Euteleostomi@clade","2":"207598@Homininae@subfamily","22":"7776@Gnathostomata@clade","26":"33213@Bilateria@clade","28":"6072@Eumetazoa@clade","7":"9526@Catarrhini@parvorder"},"species_name":"Homo sapiens","taxid":9606} Homo sapiens chromosome 5 clone CTC-454K8, complete sequence.
+ttagccctaaacttcaacagttaaattaacaaaactgctcgccagaacactacgagccac
+agcttaaaactcaaaggacctggcggtgcttcatatccct