diff --git a/passerelle/contrib/toulouse_smart/utils.py b/passerelle/contrib/toulouse_smart/utils.py
index 60a4690d..e1b2707e 100644
--- a/passerelle/contrib/toulouse_smart/utils.py
+++ b/passerelle/contrib/toulouse_smart/utils.py
@@ -19,7 +19,7 @@ from django.utils.timezone import localtime, make_aware, make_naive, utc
 
 
 def localtz_to_utc(date_time_string):
-    aware_dt_in_utc = make_aware(parse_datetime(date_time_string)).astimezone(utc)
+    aware_dt_in_utc = make_aware(parse_datetime(date_time_string), is_dst=False).astimezone(utc)
     return aware_dt_in_utc.isoformat()
 
 
diff --git a/tests/test_toulouse_smart.py b/tests/test_toulouse_smart.py
index 8adf0382..1649cd85 100644
--- a/tests/test_toulouse_smart.py
+++ b/tests/test_toulouse_smart.py
@@ -41,6 +41,7 @@ from passerelle.contrib.toulouse_smart.models import (
     WcsRequest,
     WcsRequestFile,
 )
+from passerelle.contrib.toulouse_smart.utils import localtz_to_utc, utc_to_localtz
 from tests.test_manager import login
 
 TEST_BASE_DIR = os.path.join(os.path.dirname(__file__), 'data', 'toulouse_smart')
@@ -130,6 +131,13 @@ def get_media_file(filename):
         return desc.read()
 
 
+def test_save_daylight_time_change(settings):
+    settings.TIME_ZONE = 'Europe/Paris'
+    settings.USE_TZ = True
+    assert localtz_to_utc('2022-10-30T02:19:48') == '2022-10-30T01:19:48+00:00'
+    assert utc_to_localtz('2022-10-30T01:19:48+00:00') == '2022-10-30T02:19:48'
+
+
 @mock_response(['/v1/type-intervention', None, b'<List></List>'])
 def test_empty_intervention_types(smart):
     assert smart.get_intervention_types() == []