diff --git a/backend/open_webui/retrieval/vector/dbs/opensearch.py b/backend/open_webui/retrieval/vector/dbs/opensearch.py
index dc9c35805..ed5a931c6 100644
--- a/backend/open_webui/retrieval/vector/dbs/opensearch.py
+++ b/backend/open_webui/retrieval/vector/dbs/opensearch.py
@@ -211,7 +211,7 @@ class OpenSearchClient(VectorDBBase):
                 for item in batch
             ]
             bulk(self.client, actions)
-        self.client.indices.refresh(self._get_index_name(collection_name))
+        self.client.indices.refresh(index=self._get_index_name(collection_name))
 
     def upsert(self, collection_name: str, items: list[VectorItem]):
         self._create_index_if_not_exists(
@@ -234,7 +234,7 @@ class OpenSearchClient(VectorDBBase):
                 for item in batch
             ]
             bulk(self.client, actions)
-        self.client.indices.refresh(self._get_index_name(collection_name))
+        self.client.indices.refresh(index=self._get_index_name(collection_name))
 
     def delete(
         self,
@@ -263,7 +263,7 @@ class OpenSearchClient(VectorDBBase):
             self.client.delete_by_query(
                 index=self._get_index_name(collection_name), body=query_body
             )
-        self.client.indices.refresh(self._get_index_name(collection_name))
+        self.client.indices.refresh(index=self._get_index_name(collection_name))
 
     def reset(self):
         indices = self.client.indices.get(index=f"{self.index_prefix}_*")