diff --git a/photologue/migrations/0009_regen_thumbnails.py b/photologue/migrations/0009_regen_thumbnails.py
new file mode 100644
index 0000000..b4d0028
--- /dev/null
+++ b/photologue/migrations/0009_regen_thumbnails.py
@@ -0,0 +1,31 @@
+from django.db import migrations
+
+
+def regen_thumbnails(apps, schema_editor):
+    Photo = apps.get_model("photologue", "Photo")
+    PhotoSize = apps.get_model("photologue", "PhotoSize")
+
+    try:
+        thumbnail = PhotoSize.objects.get(name="thumbnail")
+    except PhotoSize.DoesNotExist:
+        return
+
+    for photo in Photo.objects.all():
+        # Use the real model instance to access file methods
+        from photologue.models import Photo as RealPhoto
+        try:
+            real_photo = RealPhoto.objects.get(pk=photo.pk)
+            real_photo.remove_size(thumbnail)
+        except Exception:
+            pass
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("photologue", "0008_photo_dimensions"),
+    ]
+
+    operations = [
+        migrations.RunPython(regen_thumbnails, migrations.RunPython.noop),
+    ]