diff --git a/src/bapi/resources/library.py b/src/bapi/resources/library.py
index 88d5dba..4a3ba1e 100644
--- a/src/bapi/resources/library.py
+++ b/src/bapi/resources/library.py
@@ -18,7 +18,7 @@ class BookListResource(MethodResource):
     @marshal_with(PaginationResultSchema)
     def get(self, **kwargs):
         page = max(min(kwargs.get("page") or 1, 1_000_000), 1)
-        query = db.db_session.query(db.Book).filter(db.Book.deleted is None).order_by(db.Book.datetime.desc())
+        query = db.db_session.query(db.Book).filter(db.Book.deleted.is_(None)).order_by(db.Book.datetime.desc())
         length = query.count()
         displayed_books = query.offset((page - 1) * cfg.API["items-per-page"]).limit(cfg.API["items-per-page"])