diff --git a/graphiti_core/graphiti.py b/graphiti_core/graphiti.py
index 0b4e6325..2b945d9b 100644
--- a/graphiti_core/graphiti.py
+++ b/graphiti_core/graphiti.py
@@ -412,7 +412,7 @@ class Graphiti:
         except Exception as e:
             raise e
 
-    async def add_episode_bulk(self, bulk_episodes: list[RawEpisode], group_id: str | None):
+    async def add_episode_bulk(self, bulk_episodes: list[RawEpisode], group_id: str | None = None):
         """
         Process multiple episodes in bulk and update the graph.