diff --git a/media/management/commands/migrate_to_new_format.py b/media/management/commands/migrate_to_new_format.py
index da0a60a..c718b3f 100644
--- a/media/management/commands/migrate_to_new_format.py
+++ b/media/management/commands/migrate_to_new_format.py
@@ -1,8 +1,7 @@
 from django.core.management import BaseCommand
 from django.db import transaction
 from django.utils.translation import gettext_lazy as _
-from media.models import CD, Comic, Game, Manga, Novel, Review, Vinyl, \
-    OldCD, OldComic, OldGame, OldManga, OldNovel, OldReview, OldVinyl
+from media.models import CD, Comic, Game, Manga, Novel, Review, Vinyl
 from tqdm import tqdm
 
 
@@ -17,6 +16,13 @@ class Command(BaseCommand):
 
     @transaction.atomic
     def handle(self, *args, **options):  # noqa: C901
+        self.stderr.write(self.style.WARNING(
+            "Old data structure has been deleted. This script won't work "
+            "anymore (and is now useless)"))
+
+        from media.models import OldCD, OldComic, OldGame, OldManga, OldNovel, \
+            OldReview, OldVinyl
+
         # Migrate books
         for old_book_class, book_class in [(OldComic, Comic),
                                            (OldManga, Manga),
diff --git a/media/migrations/0044_auto_20211102_1254.py b/media/migrations/0044_auto_20211102_1254.py
new file mode 100644
index 0000000..a41071f
--- /dev/null
+++ b/media/migrations/0044_auto_20211102_1254.py
@@ -0,0 +1,58 @@
+# Generated by Django 2.2.24 on 2021-11-02 11:54
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('media', '0043_auto_20211023_2012'),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='oldcd',
+            name='authors',
+        ),
+        migrations.RemoveField(
+            model_name='oldcomic',
+            name='authors',
+        ),
+        migrations.RemoveField(
+            model_name='oldgame',
+            name='owner',
+        ),
+        migrations.RemoveField(
+            model_name='oldmanga',
+            name='authors',
+        ),
+        migrations.RemoveField(
+            model_name='oldnovel',
+            name='authors',
+        ),
+        migrations.DeleteModel(
+            name='OldReview',
+        ),
+        migrations.RemoveField(
+            model_name='oldvinyl',
+            name='authors',
+        ),
+        migrations.DeleteModel(
+            name='OldCD',
+        ),
+        migrations.DeleteModel(
+            name='OldComic',
+        ),
+        migrations.DeleteModel(
+            name='OldGame',
+        ),
+        migrations.DeleteModel(
+            name='OldManga',
+        ),
+        migrations.DeleteModel(
+            name='OldNovel',
+        ),
+        migrations.DeleteModel(
+            name='OldVinyl',
+        ),
+    ]