diff --git a/app/controllers/delete_nested_book_entities.py b/app/controllers/delete_nested_book_entities.py
index a3c315f..dc4f8bf 100644
--- a/app/controllers/delete_nested_book_entities.py
+++ b/app/controllers/delete_nested_book_entities.py
@@ -29,6 +29,10 @@ def delete_nested_version_entities(book_version: m.BookVersion):
 
 def delete_nested_collection_entities(collection: m.Collection):
     for sub_collection in collection.children:
+        collection.is_deleted = True
+        collection.save(False)
+        sub_collection.is_deleted = True
+        sub_collection.save(False)
         delete_nested_collection_entities(sub_collection)
     for section in collection.sections:
         section: m.Section