diff --git a/pkg/tsdb/elasticsearch/client/client.go b/pkg/tsdb/elasticsearch/client/client.go
index c96f51d396b..c14ffd6a8b0 100644
--- a/pkg/tsdb/elasticsearch/client/client.go
+++ b/pkg/tsdb/elasticsearch/client/client.go
@@ -207,7 +207,7 @@ func (c *baseClientImpl) createMultiSearchRequests(searchRequests []*SearchReque
 			header: map[string]interface{}{
 				"search_type":        "query_then_fetch",
 				"ignore_unavailable": true,
-				"index":              strings.Join(c.indices, ","),
+				"index":              c.indices,
 			},
 			body:     searchReq,
 			interval: searchReq.Interval,
diff --git a/pkg/tsdb/elasticsearch/client/client_test.go b/pkg/tsdb/elasticsearch/client/client_test.go
index 1c4895b7a5d..4d90fd71a7f 100644
--- a/pkg/tsdb/elasticsearch/client/client_test.go
+++ b/pkg/tsdb/elasticsearch/client/client_test.go
@@ -96,7 +96,7 @@ func TestClient_ExecuteMultisearch(t *testing.T) {
 		jBody, err := simplejson.NewJson(bodyBytes)
 		require.NoError(t, err)
 
-		assert.Equal(t, "metrics-2018.05.15", jHeader.Get("index").MustString())
+		assert.Equal(t, []string{"metrics-2018.05.15"}, jHeader.Get("index").MustStringArray())
 		assert.True(t, jHeader.Get("ignore_unavailable").MustBool(false))
 		assert.Equal(t, "query_then_fetch", jHeader.Get("search_type").MustString())
 		assert.Empty(t, jHeader.Get("max_concurrent_shard_requests"))
diff --git a/pkg/tsdb/elasticsearch/snapshot_test.go b/pkg/tsdb/elasticsearch/snapshot_test.go
index ff021dbac8a..312d068f0e1 100644
--- a/pkg/tsdb/elasticsearch/snapshot_test.go
+++ b/pkg/tsdb/elasticsearch/snapshot_test.go
@@ -82,7 +82,7 @@ func TestRequestSnapshots(t *testing.T) {
 	queryHeader := []byte(`
 	{
 		"ignore_unavailable": true,
-		"index": "testdb-2022.11.14",
+		"index": ["testdb-2022.11.14"],
 		"search_type": "query_then_fetch"
 	}
 	`)