diff --git a/api/core/rag/datasource/vdb/elasticsearch/elasticsearch_vector.py b/api/core/rag/datasource/vdb/elasticsearch/elasticsearch_vector.py
index c62042af80..b08811a021 100644
--- a/api/core/rag/datasource/vdb/elasticsearch/elasticsearch_vector.py
+++ b/api/core/rag/datasource/vdb/elasticsearch/elasticsearch_vector.py
@@ -178,6 +178,7 @@ class ElasticSearchVector(BaseVector):
                         Field.VECTOR.value: {  # Make sure the dimension is correct here
                             "type": "dense_vector",
                             "dims": dim,
+                            "index": True,
                             "similarity": "cosine",
                         },
                         Field.METADATA_KEY.value: {