diff --git a/elasticsearch/index.d.ts b/elasticsearch/index.d.ts
index 84c8f281f9..a0606a4961 100644
--- a/elasticsearch/index.d.ts
+++ b/elasticsearch/index.d.ts
@@ -88,6 +88,7 @@ declare module Elasticsearch {
     export interface ConfigOptions {
         host?: any;
         hosts?: any;
+        httpAuth?: string;
         log?: any;
         apiVersion?: string;
         plugins?: any;