diff --git a/oml/item/scan.py b/oml/item/scan.py
index 821cec4..8001989 100644
--- a/oml/item/scan.py
+++ b/oml/item/scan.py
@@ -50,7 +50,7 @@ def remove_missing(books=None):
             if dirty:
                 state.db.session.commit()
                 dirty = False
-            nfd_books = {unicodedata.normalize('NFD', path) for path in nfd_books}
+            nfd_books = {unicodedata.normalize('NFD', path) for path in books}
             removed = [
                 path for path in db_paths
                 if unicodedata.normalize('NFD', path) not in nfd_books