diff --git a/app/scodoc/sco_groups.py b/app/scodoc/sco_groups.py
index c68e4342ad..ca6246f4cf 100644
--- a/app/scodoc/sco_groups.py
+++ b/app/scodoc/sco_groups.py
@@ -844,9 +844,11 @@ def create_group(partition_id, group_name="", default=False) -> GroupDescr:
     if not GroupDescr.check_name(partition, group_name):
         raise ScoValueError(f"Le groupe {group_name} existe déjà dans cette partition")
 
-    new_numero = (
-        max([g.numero if g.numero is not None else 0 for g in partition.groups]) + 1
-    )
+    numeros = [g.numero if g.numero is not None else 0 for g in partition.groups]
+    if len(numeros) > 0:
+        new_numero = max(numeros) + 1
+    else:
+        new_numero = 0
     group = GroupDescr(partition=partition, group_name=group_name, numero=new_numero)
     db.session.add(group)
     db.session.commit()
diff --git a/sco_version.py b/sco_version.py
index 60ae7efa10..e793d4d3be 100644
--- a/sco_version.py
+++ b/sco_version.py
@@ -1,7 +1,7 @@
 # -*- mode: python -*-
 # -*- coding: utf-8 -*-
 
-SCOVERSION = "9.3.30"
+SCOVERSION = "9.3.31"
 
 SCONAME = "ScoDoc"