diff --git a/seminar/migrations/0080_zruseni_claneknode_a_konferanode.py b/seminar/migrations/0080_zruseni_claneknode_a_konferanode.py
index bfc5b1bd..13d083f9 100644
--- a/seminar/migrations/0080_zruseni_claneknode_a_konferanode.py
+++ b/seminar/migrations/0080_zruseni_claneknode_a_konferanode.py
@@ -24,6 +24,13 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
+        migrations.DeleteModel(
+            name='Konfery_Ucastnici',
+        ),
+        migrations.RemoveField(
+            model_name='konfera',
+            name='ucastnici',
+        ),
         migrations.CreateModel(
             name='OrgTextNode',
             fields=[
@@ -38,18 +45,14 @@ class Migration(migrations.Migration):
             },
             bases=('seminar.treenode',),
         ),
+        migrations.RemoveField(
+            model_name='konfera',
+            name='id',
+        ),
         migrations.RenameModel(
             old_name='OtisteneReseniNode',
             new_name='ReseniNode',
         ),
-        migrations.RemoveField(
-            model_name='konferanode',
-            name='konfera',
-        ),
-        migrations.RemoveField(
-            model_name='konferanode',
-            name='treenode_ptr',
-        ),
         migrations.RemoveField(
             model_name='clanek',
             name='cislo',
@@ -65,14 +68,9 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='konfera',
             name='problem_ptr',
-            field=models.OneToOneField(auto_created=True, null=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='seminar.Problem'),
+            field=models.OneToOneField(auto_created=True, null=False, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='seminar.Problem'),
             preserve_default=False,
         ),
-        migrations.RunPython(vyrob_dummy_problemy),
-        migrations.RemoveField(
-            model_name='konfera',
-            name='id',
-        ),
         migrations.RemoveField(
             model_name='konfera',
             name='nazev',
@@ -100,4 +98,24 @@ class Migration(migrations.Migration):
         migrations.DeleteModel(
             name='KonferaNode',
         ),
+        migrations.CreateModel(
+            name='Konfery_Ucastnici',
+            fields=[
+                ('id', models.AutoField(primary_key=True, serialize=False)),
+                ('poznamka', models.TextField(blank=True, help_text='Neveřejná poznámka k účasti (plain text)', verbose_name='neveřejná poznámka')),
+                ('konfera', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='seminar.Konfera', verbose_name='konfera')),
+                ('resitel', models.ForeignKey(on_delete=django.db.models.deletion.PROTECT, to='seminar.Resitel', verbose_name='řešitel')),
+            ],
+            options={
+                'verbose_name': 'Účast na konfeře',
+                'verbose_name_plural': 'Účasti na konfeře',
+                'db_table': 'seminar_konfery_ucastnici',
+                'ordering': ['konfera', 'resitel'],
+            },
+        ),
+        migrations.AddField(
+            model_name='konfera',
+            name='ucastnici',
+            field=models.ManyToManyField(help_text='Seznam účastníků konfery', through='seminar.Konfery_Ucastnici', to='seminar.Resitel', verbose_name='účastníci konfery'),
+        ),
     ]