diff --git a/app/api/partitions.py b/app/api/partitions.py
index 1dac1b8b5d..bbae592972 100644
--- a/app/api/partitions.py
+++ b/app/api/partitions.py
@@ -205,9 +205,10 @@ def group_remove_etud(group_id: int, etudid: int):
             query.join(Partition).join(FormSemestre).filter_by(dept_id=g.scodoc_dept_id)
         )
     group = query.first_or_404()
-    group.etuds.remove(etud)
-    db.session.commit()
-    sco_cache.invalidate_formsemestre(group.partition.formsemestre_id)
+    if etud in group.etuds:
+        group.etuds.remove(etud)
+        db.session.commit()
+        sco_cache.invalidate_formsemestre(group.partition.formsemestre_id)
     return jsonify({"group_id": group_id, "etudid": etudid})
 
 
diff --git a/scodoc.py b/scodoc.py
index 253e62aa81..ef464a0990 100755
--- a/scodoc.py
+++ b/scodoc.py
@@ -25,11 +25,13 @@ from app import models
 
 from app.auth.models import User, Role, UserRole
 from app.scodoc.sco_logos import make_logo_local
+from app.models import departements
 from app.models import Formation, UniteEns, Matiere, Module
 from app.models import FormSemestre, FormSemestreInscription
-from app.models import ModuleImpl, ModuleImplInscription
+from app.models import GroupDescr
 from app.models import Identite
-from app.models import departements
+from app.models import ModuleImpl, ModuleImplInscription
+from app.models import Partition
 from app.models.evaluations import Evaluation
 from app.entreprises.models import entreprises_reset_database
 from app.scodoc.sco_permissions import Permission
@@ -62,6 +64,7 @@ def make_shell_context():
         "Formation": Formation,
         "FormSemestre": FormSemestre,
         "FormSemestreInscription": FormSemestreInscription,
+        "GroupDescr": GroupDescr,
         "Identite": Identite,
         "login_user": login_user,
         "logout_user": logout_user,
@@ -71,6 +74,7 @@ def make_shell_context():
         "Module": Module,
         "ModuleImpl": ModuleImpl,
         "ModuleImplInscription": ModuleImplInscription,
+        "Partition": Partition,
         "ndb": ndb,
         "notes": notes,
         "np": np,
diff --git a/tests/api/setup_test_api.py b/tests/api/setup_test_api.py
index 4a794513ef..0f28617172 100644
--- a/tests/api/setup_test_api.py
+++ b/tests/api/setup_test_api.py
@@ -50,7 +50,7 @@ def GET(path: str, headers={}, errmsg=None, dept=None):
         url = SCODOC_URL + f"/ScoDoc/{dept}/api" + path
     else:
         url = API_URL + path
-    r = requests.get(url, headers=headers, verify=CHECK_CERTIFICATE)
+    r = requests.get(url, headers=headers or CUR_HEADERS, verify=CHECK_CERTIFICATE)
     if r.status_code != 200:
         raise APIError(errmsg or f"""erreur status={r.status_code} !\n{r.text}""")
     return r.json()  # decode la reponse JSON
diff --git a/tests/api/test_api_partitions.py b/tests/api/test_api_partitions.py
index 14bd2d7bd8..bf9e6b3921 100644
--- a/tests/api/test_api_partitions.py
+++ b/tests/api/test_api_partitions.py
@@ -62,9 +62,11 @@ def test_formsemestre_partition(api_headers):
     /partition/<int:partition_id>/group/create
     /partition/<int:partition_id>
     /partition/<int:partition_id/delete
+    /group/<int:group_id>/set_etudiant/<int:etudid>
     """
+    headers = api_headers
     formsemestre_id = 1
-    partitions = GET(f"/formsemestre/{formsemestre_id}/partitions", headers=api_headers)
+    partitions = GET(f"/formsemestre/{formsemestre_id}/partitions", headers=headers)
     # au départ, pas de partitions
     assert partitions == {}
     # --- Création partition
@@ -76,7 +78,7 @@ def test_formsemestre_partition(api_headers):
     partition_r = POST_JSON(
         f"/formsemestre/{formsemestre_id}/partition/create",
         partition_d,
-        headers=api_headers,
+        headers=headers,
     )
     assert isinstance(partition_r, dict)
     assert partition_r["partition_name"] == partition_d["partition_name"]
@@ -86,12 +88,12 @@ def test_formsemestre_partition(api_headers):
     group_r = POST_JSON(
         f"/partition/{partition_r['id']}/group/create",
         group_d,
-        headers=api_headers,
+        headers=headers,
     )
     assert isinstance(group_r, dict)
     assert group_r["group_name"] == group_d["group_name"]
     # --- Liste groupes de la partition
-    partition = GET(f"/partition/{partition_r['id']}", headers=api_headers)
+    partition = GET(f"/partition/{partition_r['id']}", headers=headers)
     assert isinstance(partition, dict)
     assert partition["id"] == partition_r["id"]
     assert isinstance(partition["groups"], dict)
@@ -99,8 +101,29 @@ def test_formsemestre_partition(api_headers):
     group = partition["groups"][str(group_r["id"])]  # nb: str car clés json en string
     assert group["group_name"] == group_d["group_name"]
 
+    # Place un étudiant dans le groupe
+    etud = GET(f"/formsemestre/{formsemestre_id}/etudiants", headers=headers)[0]
+    repl = POST_JSON(f"/group/{group['id']}/set_etudiant/{etud['id']}", headers=headers)
+    assert isinstance(repl, dict)
+    assert repl["group_id"] == group["id"]
+    assert repl["etudid"] == etud["id"]
+    #
+    etuds = GET(f"/group/{group['id']}/etudiants", headers=headers)
+    assert len(etuds) == 1
+    assert etuds[0]["id"] == etud["id"]
+    # Retire l'étudiant du groupe
+    repl = POST_JSON(
+        f"/group/{group['id']}/remove_etudiant/{etud['id']}", headers=headers
+    )
+    assert len(GET(f"/group/{group['id']}/etudiants", headers=headers)) == 0
+
+    # Le retire à nouveau ! (bug #465)
+    repl = POST_JSON(
+        f"/group/{group['id']}/remove_etudiant/{etud['id']}", headers=headers
+    )
+    assert repl["group_id"] == group["id"]
     # Delete partition
-    repl = POST_JSON(f"/partition/{partition_r['id']}/delete", headers=api_headers)
+    repl = POST_JSON(f"/partition/{partition_r['id']}/delete", headers=headers)
     assert repl["OK"] is True