diff --git a/packages/grpc-js/src/channel-options.ts b/packages/grpc-js/src/channel-options.ts
index 8c4756ec7..f316a58a0 100644
--- a/packages/grpc-js/src/channel-options.ts
+++ b/packages/grpc-js/src/channel-options.ts
@@ -33,7 +33,9 @@ export interface ChannelOptions {
   'grpc.max_send_message_length'?: number;
   'grpc.max_receive_message_length'?: number;
   'grpc.enable_http_proxy'?: number;
-  [key: string]: string | number | undefined;
+  'grpc.http_connect_target'?: string;
+  'grpc.http_connect_creds'?: string;
+  [key: string]: any;
 }
 
 /**