diff --git a/app/scodoc/sco_groups_view.py b/app/scodoc/sco_groups_view.py
index 667a292b4..871d09569 100644
--- a/app/scodoc/sco_groups_view.py
+++ b/app/scodoc/sco_groups_view.py
@@ -364,11 +364,11 @@ class DisplayedGroupsInfos(object):
                 self.formsemestre = sem
             self.members.extend(group_members)
             groups_titles.append(group_tit)
-            if group["partition_name"] == None:
+            if group["partition_name"] is None:
                 self.tous_les_etuds_du_sem = True
             else:
                 # liste les partitions explicitement sélectionnés (= des groupes de group_ids)
-                selected_partitions.add((group["numero"], group["partition_id"]))
+                selected_partitions.add((group["numero"] or 0, group["partition_id"]))
 
         self.selected_partitions = [
             x[1] for x in sorted(list(selected_partitions))