diff --git a/aleksis/apps/alsijil/migrations/0011_tardiness_positive.py b/aleksis/apps/alsijil/migrations/0011_tardiness_positive.py
index 8d9afa8e0f795a6a83f4dd32ea6b1eca465cad0f..584a560caf51ee12cf92d1f6fdb3e6af7bd0f0d0 100644
--- a/aleksis/apps/alsijil/migrations/0011_tardiness_positive.py
+++ b/aleksis/apps/alsijil/migrations/0011_tardiness_positive.py
@@ -3,6 +3,11 @@
 from django.db import migrations, models
 
 
+def fix_negative_tardiness(apps, schema_editor):
+    PersonalNote = apps.get_model("alsijil", "PersonalNote")
+    PersonalNote.objects.filter(late__lt=0).update(late=0)
+
+
 class Migration(migrations.Migration):
 
     dependencies = [
@@ -10,6 +15,7 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
+        migrations.RunPython(fix_negative_tardiness),
         migrations.AlterField(
             model_name='personalnote',
             name='late',