diff --git a/app/forms/scolar/groups_form.py b/app/forms/scolar/groups_form.py
index 33a0d7521..1330224c4 100644
--- a/app/forms/scolar/groups_form.py
+++ b/app/forms/scolar/groups_form.py
@@ -53,4 +53,6 @@ class FeuilleAppelPreForm(FlaskForm):
         },
     )
 
-    submit = SubmitField("Télécharger la liste d'émargement")
+    submit = SubmitField(
+        "Télécharger la liste d'émargement", id="btn-submit", name="btn-submit"
+    )
diff --git a/app/scodoc/sco_groups_view.py b/app/scodoc/sco_groups_view.py
index 541589bb5..3a16c98ff 100644
--- a/app/scodoc/sco_groups_view.py
+++ b/app/scodoc/sco_groups_view.py
@@ -39,7 +39,7 @@ from urllib.parse import parse_qs
 from flask import url_for, g, render_template, request
 from flask_login import current_user
 
-from app import db
+from app import db, log
 from app.models import FormSemestre, Identite, ScolarEvent
 import app.scodoc.sco_utils as scu
 from app.scodoc import html_sco_header
@@ -225,7 +225,7 @@ def menu_groups_choice(
     submit_on_change=False,
     default_deselect_others=True,
     html_export=True,
-    change_event=None,
+    change_event=None,  # XXX ???
 ):
     """menu pour selection groupes
     group_ids est la liste des groupes actuellement sélectionnés
@@ -369,6 +369,7 @@ class DisplayedGroupsInfos:
             try:
                 group_ids = [int(g) for g in group_ids]
             except ValueError as exc:
+                log(f"DisplayedGroupsInfos: invalid group_id '{group_ids}'")
                 raise ScoValueError(
                     "identifiant de groupe invalide (mettre à jour vos bookmarks ?)"
                 ) from exc
@@ -973,7 +974,7 @@ def tab_absences_html(groups_infos, etat=None):
             scodoc_dept=g.scodoc_dept,
             formsemestre_id=groups_infos.formsemestre_id,
         )
-        + "&"
+        + "?"
         + groups_infos.groups_query_args
     )
 
diff --git a/app/templates/scolar/formulaire_feuille_appel.j2 b/app/templates/scolar/formulaire_feuille_appel.j2
index ea7f133a5..8c93e15e7 100644
--- a/app/templates/scolar/formulaire_feuille_appel.j2
+++ b/app/templates/scolar/formulaire_feuille_appel.j2
@@ -19,7 +19,13 @@
 <h2>Préparation de la feuille d'émargement : <span style="color:crimson">{{group_name}}</span></h2>
 
 <div class="scobox">
-    <form action="" method="post">
+    <form
+        id="feuille_emargement"
+        action="{{request.base_url}}"
+        method="post"
+        onsubmit="serializeGroupIds(event)"
+    >
+        {{ form.hidden_tag() }}
         <div class="infos-button">Groupes&nbsp;: {{grp|safe}}</div>
 
         <div class="part">
@@ -50,4 +56,24 @@
 {% include "sco_timepicker.j2" %}
 <script src="{{scu.STATIC_DIR}}/js/groups_view.js"></script>
 <script src="{{scu.STATIC_DIR}}/libjs/purl.js"></script>
+<script>
+function serializeGroupIds(event) {
+    // Dealing with multiselect
+    event.preventDefault();
+    var form = document.getElementById("feuille_emargement");
+    var groupIdsField = form.elements["group_ids"];
+
+    // Check if the group_ids field exists and is an array
+    if (groupIdsField && Array.isArray(groupIdsField.value)) {
+        // Convert the array to a comma-separated string
+        var serializedValue = groupIdsField.value.join(',');
+
+        // Replace the field's value with the serialized string
+        groupIdsField.value = serializedValue;
+    }
+
+    // Now submit the form
+    form.submit();
+}
+</script>
 {% endblock scripts %}
\ No newline at end of file
diff --git a/app/views/groups.py b/app/views/groups.py
index 4f8e815dc..2dc869321 100644
--- a/app/views/groups.py
+++ b/app/views/groups.py
@@ -5,16 +5,15 @@ Nouvelles vues pour les groupes
 
 from flask import render_template, request
 
-
+from app import log
 from app.decorators import (
     scodoc,
     permission_required,
 )
 from app.forms.scolar import groups_form
-from app.models import (
-    FormSemestre,
-)
+from app.models import FormSemestre
 from app.scodoc.sco_excel import excel_feuille_listeappel
+from app.scodoc.sco_exceptions import ScoValueError
 from app.scodoc.sco_groups_view import DisplayedGroupsInfos, menu_groups_choice
 from app.scodoc.sco_permissions import Permission
 from app.scodoc import sco_utils as scu
@@ -22,34 +21,35 @@ from app.views import ScoData
 from app.views import scolar_bp as bp
 
 
-@bp.route("/formulaire_feuille_appel", methods=["GET", "POST"])
+@bp.route("/formulaire_feuille_appel/<int:formsemestre_id>", methods=["GET", "POST"])
 @scodoc
 @permission_required(Permission.ScoView)
-def formulaire_feuille_appel():
+def formulaire_feuille_appel(formsemestre_id: int):
     """Formulaire de feuille d'appel
 
-    GET : Affiche le formulaire de remplissage de la feuille d'appel
-    POST : Retourne la feuille d'appelle correspondante
+    GET Affiche le formulaire de remplissage de la feuille d'appel
+    POST (soumission) retourne la feuille d'appel correspondante
 
     QUERY
     -----
-    formsemestre_id:<int:formsemestre_id>
     group_ids:<list:<int:group_id>>
 
     """
-    formsemestre_id: int = request.args.get("formsemestre_id")
-    try:
-        formsemestre_id = int(formsemestre_id)
-    except ValueError:
-        formsemestre_id = None
+    formsemestre = FormSemestre.get_formsemestre(formsemestre_id)
 
-    formsemestre: FormSemestre = FormSemestre.get_formsemestre(formsemestre_id)
+    if request.method == "GET":
+        group_ids: list[int] = request.args.getlist("group_ids")
+        data = {"group_ids": group_ids}
+    else:
+        group_ids_str = request.form.get("group_ids")
+        try:
+            group_ids = [int(gid) for gid in group_ids_str.split(",") if gid]
+        except ValueError as exc:
+            log(f"formulaire_feuille_appel: group_ids invalide: {group_ids_str[:100]}")
+            raise ScoValueError("groupes invalides") from exc
+        data = {}
 
-    group_ids: list[int] = request.args.getlist("group_ids")
-
-    form: groups_form.FeuilleAppelPreForm = groups_form.FeuilleAppelPreForm(
-        request.form
-    )
+    form = groups_form.FeuilleAppelPreForm(request.form, data=data)
 
     groups_infos = DisplayedGroupsInfos(
         group_ids,
@@ -57,7 +57,7 @@ def formulaire_feuille_appel():
         select_all_when_unspecified=True,
     )
 
-    if request.method == "POST":
+    if form.validate_on_submit():
         edt_params: dict = {
             "date": form.date.data or "",
             "heure": form.heure.data or "",
@@ -65,14 +65,6 @@ def formulaire_feuille_appel():
             "ens": form.ens.data or "",
         }
 
-        form_group_ids: list[str] = request.form.get("group_ids", "").split(",")
-        if form_group_ids:
-            groups_infos = DisplayedGroupsInfos(
-                form_group_ids,
-                formsemestre_id=formsemestre_id,
-                select_all_when_unspecified=True,
-            )
-
         xls = excel_feuille_listeappel(
             groups_infos.formsemestre,
             groups_infos.groups_titles,
@@ -90,4 +82,5 @@ def formulaire_feuille_appel():
         form=form,
         group_name=groups_infos.groups_titles,
         grp=menu_groups_choice(groups_infos, html_export=False),
+        formsemestre_id=formsemestre_id,
     )