diff --git a/libs/langchain/langchain/chains/rl_chain/pick_best_chain.py b/libs/langchain/langchain/chains/rl_chain/pick_best_chain.py
index afc7fc1e301..1155d03a1b0 100644
--- a/libs/langchain/langchain/chains/rl_chain/pick_best_chain.py
+++ b/libs/langchain/langchain/chains/rl_chain/pick_best_chain.py
@@ -60,6 +60,7 @@ class PickBestFeatureEmbedder(base.Embedder[PickBestEvent]):
 
         if model is None:
             from sentence_transformers import SentenceTransformer
+
             model = SentenceTransformer("all-mpnet-base-v2")
 
         self.model = model