diff --git a/opensearchutil/bulk_indexer.go b/opensearchutil/bulk_indexer.go
index 3f08cec11..f56ceaca8 100644
--- a/opensearchutil/bulk_indexer.go
+++ b/opensearchutil/bulk_indexer.go
@@ -133,7 +133,7 @@ type bulkActionMetadata struct {
 	Routing             *string     `json:"routing,omitempty"`
 	Version             *int64      `json:"version,omitempty"`
 	VersionType         *string     `json:"version_type,omitempty"`
-	IfSeqNum            *int64      `json:"if_seq_num,omitempty"`
+	IfSeqNum            *int64      `json:"if_seq_no,omitempty"`
 	IfPrimaryTerm       *int64      `json:"if_primary_term,omitempty"`
 	WaitForActiveShards interface{} `json:"wait_for_active_shards,omitempty"`
 	Refresh             *string     `json:"refresh,omitempty"`
diff --git a/opensearchutil/bulk_indexer_internal_test.go b/opensearchutil/bulk_indexer_internal_test.go
index a5c909ba7..ff8539d64 100644
--- a/opensearchutil/bulk_indexer_internal_test.go
+++ b/opensearchutil/bulk_indexer_internal_test.go
@@ -678,7 +678,18 @@ func TestBulkIndexer(t *testing.T) {
 				`{"index":{"_index":"test","_id":"42"}}` + "\n",
 			},
 			{
-				"with version and no document",
+				"with if_seq_no and if_primary_term",
+				args{BulkIndexerItem{
+					Action:        "index",
+					DocumentID:    "42",
+					Index:         "test",
+					IfSeqNum:      int64Pointer(5),
+					IfPrimaryTerm: int64Pointer(1),
+				}},
+				`{"index":{"_index":"test","_id":"42","if_seq_no":5,"if_primary_term":1}}` + "\n",
+			},
+			{
+				"with version and no document, if_seq_no, and if_primary_term",
 				args{BulkIndexerItem{
 					Action:  "index",
 					Index:   "test",