diff --git a/backend/.env.example b/backend/.env.example
index 2b1db19..37ba235 100644
--- a/backend/.env.example
+++ b/backend/.env.example
@@ -49,6 +49,7 @@ VECTOR_STORE_COLLECTION=default
 # Specify this if you are using a local vector database.
 # Otherwise, use VECTOR_STORE__HOST and VECTOR_STORE__PORT config above
 VECTOR_STORE_PATH=./storage_vector
+BM_RETRIEVER_PATH =./storage_bm