diff --git a/pylate/indexes/base.py b/pylate/indexes/base.py
index 0032e8b..9a59292 100644
--- a/pylate/indexes/base.py
+++ b/pylate/indexes/base.py
@@ -17,6 +17,7 @@ def add_documents(
         self,
         documents_ids: list[str],
         documents_embeddings: list[list[list[int | float]]],
+        batch_size: int,
     ) -> None:
         pass