diff --git a/migration/migration.py b/migration/migration.py
index 350b1573c..77f589c2e 100644
--- a/migration/migration.py
+++ b/migration/migration.py
@@ -23,7 +23,8 @@
 """
 import sys
 import os
-from threading import Lock
+from threading import Thread, Lock
+from queue import Queue
 
 from cli import options
 from sonar import exceptions, errcodes, utilities, version
@@ -104,27 +105,25 @@ def __remove_chars_at_end(file: str, nb_bytes: int) -> None:
         fd.truncate()
 
 
-def __add_project_header(file: str) -> None:
-    """Writes the configuration in file"""
-    with open(file, mode="a", encoding="utf-8") as fd:
-        print(',\n   "projects": {\n', file=fd)
-
-
-def __add_project_footer(file: str) -> None:
-    """Closes projects section"""
-    __remove_chars_at_end(file, 2)
-    with open(file, mode="a", encoding="utf-8") as fd:
-        print("\n   }\n}", file=fd)
-
-
-def write_project(project_json: dict[str, any], file: str) -> None:
+def write_projects(queue: Queue, file: str) -> None:
     """
-    writes a project JSON in a file
+    Thread to write projects in the JSON file
     """
-    key = project_json.pop("key")
-    with _WRITE_LOCK:
-        with utilities.open_file(file, mode="a") as fd:
-            print(f'"{key}": {utilities.json_dump(project_json)},', file=fd)
+    done = False
+    prefix = ""
+    with utilities.open_file(file, mode="a") as fd:
+        print('"   projects": {', file=fd)
+        while not done:
+            project_json = queue.get()
+            done = project_json is None
+            if not done:
+                log.info("Writing project '%s'", project_json["key"])
+                key = project_json.pop("key")
+                print(f'{prefix}"{key}": {utilities.json_dump(project_json)}', end="", file=fd)
+                prefix = ",\n"
+            queue.task_done()
+        print("\n}", file=fd, end="")
+    log.info("Writing projects complete")
 
 
 def __write_export(config: dict[str, str], file: str) -> None:
@@ -179,12 +178,20 @@ def __export_config(endpoint: platform.Platform, what: list[str], **kwargs) -> N
     #    sq_settings = utilities.inline_lists(sq_settings, exceptions=("conditions",))
 
     log.info("Exporting project migration data streaming projects in '%s'", kwargs[options.REPORT_FILE])
-    export_settings["WRITE_CALLBACK"] = write_project
     __remove_chars_at_end(kwargs[options.REPORT_FILE], 3)
-    __add_project_header(kwargs[options.REPORT_FILE])
+    with utilities.open_file(kwargs[options.REPORT_FILE], mode="a") as fd:
+        print(",", file=fd)
+    q = Queue(maxsize=0)
+    worker = Thread(target=write_projects, args=(q, kwargs[options.REPORT_FILE]))
+    worker.setDaemon(True)
+    worker.setName("WriteThread")
+    worker.start()
+    export_settings["WRITE_QUEUE"] = q
     projects.export(endpoint, export_settings=export_settings, key_list=key_list)
-    __add_project_footer(kwargs[options.REPORT_FILE])
+    q.join()
     log.info("Exporting migration data from %s completed", kwargs["url"])
+    with utilities.open_file(kwargs[options.REPORT_FILE], mode="a") as fd:
+        print("\n}", file=fd)
 
 
 def main() -> None:
diff --git a/sonar/projects.py b/sonar/projects.py
index 7e192a728..ab94465d8 100644
--- a/sonar/projects.py
+++ b/sonar/projects.py
@@ -1478,8 +1478,8 @@ def __export_thread(queue: Queue[Project], results: dict[str, str], export_setti
     while not queue.empty():
         project = queue.get()
         exp_json = project.export(export_settings=export_settings)
-        if export_settings.get("WRITE_CALLBACK", None):
-            export_settings["WRITE_CALLBACK"](exp_json, export_settings["file"])
+        if export_settings.get("WRITE_QUEUE", None):
+            export_settings["WRITE_QUEUE"].put(exp_json)
         else:
             results[project.key] = exp_json
             results[project.key].pop("key", None)
@@ -1489,6 +1489,7 @@ def __export_thread(queue: Queue[Project], results: dict[str, str], export_setti
         if nb % 10 == 0 or nb == tot:
             log.info("%d/%d projects exported (%d%%)", nb, tot, (nb * 100) // tot)
         queue.task_done()
+    log.info("Putting DONE in queue %s", str(export_settings["WRITE_QUEUE"]))
 
 
 def export(endpoint: pf.Platform, export_settings: types.ConfigSettings, key_list: types.KeyList = None) -> types.ObjectJsonRepr:
@@ -1518,6 +1519,7 @@ def export(endpoint: pf.Platform, export_settings: types.ConfigSettings, key_lis
         worker.setName(f"ProjectExport{i}")
         worker.start()
     q.join()
+    export_settings["WRITE_QUEUE"].put(None)
     return dict(sorted(project_settings.items()))
 
 
diff --git a/test/test_sonarcloud.py b/test/test_sonarcloud.py
index b02c4931d..faa314e0f 100644
--- a/test/test_sonarcloud.py
+++ b/test/test_sonarcloud.py
@@ -38,6 +38,7 @@
 MY_ORG_1 = "okorach"
 MY_ORG_2 = "okorach-github"
 
+
 def test_sc_config_export() -> None:
     """test_sc_config_export"""
     util.clean(util.JSON_FILE)