diff --git a/report_py3o_fusion_server/models/py3o_report.py b/report_py3o_fusion_server/models/py3o_report.py
index 6e6cf507..361d8cd0 100644
--- a/report_py3o_fusion_server/models/py3o_report.py
+++ b/report_py3o_fusion_server/models/py3o_report.py
@@ -96,7 +96,7 @@ class Py3oReport(models.TransientModel):
             )
 
         chunk_size = 1024
-        with open(result_path, 'w+') as fd:
+        with open(result_path, 'w+b') as fd:
             for chunk in r.iter_content(chunk_size):
                 fd.write(chunk)
         end_chrono = datetime.now()
diff --git a/report_py3o_fusion_server/tests/test_report_py3o_fusion_server.py b/report_py3o_fusion_server/tests/test_report_py3o_fusion_server.py
index 6fb4d0e7..773aae5f 100644
--- a/report_py3o_fusion_server/tests/test_report_py3o_fusion_server.py
+++ b/report_py3o_fusion_server/tests/test_report_py3o_fusion_server.py
@@ -9,7 +9,7 @@ from odoo.addons.report_py3o.tests import test_report_py3o
     'requests.post', mock.Mock(
         return_value=mock.Mock(
             status_code=200,
-            iter_content=mock.Mock(return_value=['test_result']),
+            iter_content=mock.Mock(return_value=[b'test_result']),
         )
     )
 )