diff --git a/app/static/js/releve-but.js b/app/static/js/releve-but.js
index b0ad3443..dfa0fa92 100644
--- a/app/static/js/releve-but.js
+++ b/app/static/js/releve-but.js
@@ -220,10 +220,8 @@ class releveBUT extends HTMLElement {
 				<div>Min. promo. :</div><div>${data.semestre.notes.min}</div>
 			</div>
 			${(() => {
-				if (data.semestre.rang.groupes == null) {
-					return "";
-				}
-				if (Object.keys(data.semestre.rang.groupes).length == 0) {
+				if ((!data.semestre.rang.groupes) ||
+					(Object.keys(data.semestre.rang.groupes).length == 0)) {
 					return "";
 				}
 				let output = "";
diff --git a/app/views/absences.py b/app/views/absences.py
index 520609ef..9e4d5b87 100644
--- a/app/views/absences.py
+++ b/app/views/absences.py
@@ -1380,8 +1380,10 @@ def _ProcessBilletAbsence(
 @scodoc
 @permission_required(Permission.ScoAbsChange)
 @scodoc7func
-def process_billet_absence_form(billet_id):
+def process_billet_absence_form(billet_id: int):
     """Formulaire traitement d'un billet"""
+    if not isinstance(billet_id, int):
+        raise abort(404, "billet_id invalide")
     billet: BilletAbsence = (
         BilletAbsence.query.filter_by(id=billet_id)
         .join(Identite)