diff --git a/aleksis/apps/chronos/migrations/0009_automaticplan.py b/aleksis/apps/chronos/migrations/0009_automaticplan.py
index 573c87450c0e67d512b3024986e75fc0eb42d681..1bcc9f3c28c5d832914c7b5c15993a1bbee85208 100644
--- a/aleksis/apps/chronos/migrations/0009_automaticplan.py
+++ b/aleksis/apps/chronos/migrations/0009_automaticplan.py
@@ -1,5 +1,6 @@
-# Generated by Django 3.2.5 on 2021-08-03 18:30
+# Generated by Django 3.2.4 on 2021-08-05 14:20
 
+import aleksis.core.managers
 import django.core.validators
 from django.db import migrations, models
 import django.db.models.deletion
@@ -20,12 +21,15 @@ class Migration(migrations.Migration):
                 ('livedocument_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='resint.livedocument')),
                 ('number_of_days', models.PositiveIntegerField(default=1, validators=[django.core.validators.MinValueValidator(1)], verbose_name='Number of days shown in the plan')),
                 ('show_header_box', models.BooleanField(default=True, help_text='The header box shows affected teachers/groups.', verbose_name='Show header box')),
-                ('last_substitutions_revision', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='reversion.revision', verbose_name='Revision which triggered the last update', editable=False)),
+                ('last_substitutions_revision', models.ForeignKey(blank=True, editable=False, null=True, on_delete=django.db.models.deletion.SET_NULL, to='reversion.revision', verbose_name='Revision which triggered the last update')),
             ],
             options={
                 'verbose_name': 'Automatic plan',
                 'verbose_name_plural': 'Automatic plans',
             },
             bases=('resint.livedocument',),
+            managers=[
+                ('objects', aleksis.core.managers.PolymorphicCurrentSiteManager()),
+            ],
         ),
     ]