diff --git a/passerelle/contrib/isere_ens/models.py b/passerelle/contrib/isere_ens/models.py
index 3cf283f2..4730aae4 100644
--- a/passerelle/contrib/isere_ens/models.py
+++ b/passerelle/contrib/isere_ens/models.py
@@ -31,6 +31,7 @@ from passerelle.utils.jsonresponse import APIError
 API_VERSION = [
     ('1.0.0', '1.0.0'),
     ('2.1.0', '2.1.0'),
+    ('2.1.1', '2.1.1'),
 ]
 API_VERSION_DEFAULT = '1.0.0'
 
@@ -98,7 +99,7 @@ SITE_BOOKING_SCHOOL_SCHEMA = {
                 "pattern": "^[0-9]*$",
             },
             "group": {
-                "description": "school group id (API v2.1.0, use applicant if empty)",
+                "description": "school group id (API v2.1.0/v2.1.1, use applicant if empty)",
                 "type": "string",
                 "pattern": "^[0-9]*$",
             },
@@ -461,7 +462,7 @@ class IsereENS(BaseResource, HTTPResource):
             payload['applicant'] = post_data['applicant']
         else:
             raise APIError(
-                'group or applicant are mandatory (API v2.1.0)',
+                'group or applicant are mandatory (API v2.1.0/v2.1.1)',
                 err_code='bad-request',
                 http_status=400,
             )
@@ -487,7 +488,7 @@ class IsereENS(BaseResource, HTTPResource):
         display_order=5,
         perm="can_access",
         parameters={
-            "code": {"description": _('Booking Code (API v1.0.0) or External ID (API v2.1.0)')},
+            "code": {"description": _('Booking Code (API v1.0.0) or External ID (API v2.1.0/v2.1.1)')},
         },
     )
     def get_site_booking(self, request, code):
diff --git a/tests/test_isere_ens.py b/tests/test_isere_ens.py
index f1034300..99c7653c 100644
--- a/tests/test_isere_ens.py
+++ b/tests/test_isere_ens.py
@@ -518,13 +518,13 @@ def test_post_book(mocked_post, app, setup, api_version):
     response = app.post_json(endpoint, params=book, status=400)
     assert response.json['err'] == 'bad-request'
     assert response.json['data'] is None
-    assert response.json['err_desc'] == 'group or applicant are mandatory (API v2.1.0)'
+    assert response.json['err_desc'] == 'group or applicant are mandatory (API v2.1.0/v2.1.1)'
 
     del book['group']
     response = app.post_json(endpoint, params=book, status=400)
     assert response.json['err'] == 'bad-request'
     assert response.json['data'] is None
-    assert response.json['err_desc'] == 'group or applicant are mandatory (API v2.1.0)'
+    assert response.json['err_desc'] == 'group or applicant are mandatory (API v2.1.0/v2.1.1)'
 
     book['applicant'] = 'ecole 1'
     response = app.post_json(endpoint, params=book)