diff --git a/passerelle/apps/cartads_cs/models.py b/passerelle/apps/cartads_cs/models.py
index e299a27b..d26002cb 100644
--- a/passerelle/apps/cartads_cs/models.py
+++ b/passerelle/apps/cartads_cs/models.py
@@ -715,11 +715,12 @@ class AbstractCartaDSCS(BaseResource):
                 )
         dossier.save()
         signer = Signer(salt='cart@ds_cs/dossier')
-        dossier.notification_url = request.build_absolute_uri(
-                reverse('generic-endpoint', kwargs={
+        notification_base_url = reverse('generic-endpoint', kwargs={
                     'connector': self.get_connector_slug(),
                     'slug': self.slug,
-                    'endpoint': 'notification'})) + '/%s/' % signer.sign(str(dossier.id))
+                    'endpoint': 'notification'})
+        dossier.notification_url = request.build_absolute_uri(
+                notification_base_url + '/%s/' % signer.sign(str(dossier.id)))
         dossier.save()
         if name_id:
             dossier.subscribers.add(CartaDSSubscriber.objects.get_or_create(name_id=name_id)[0])