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;
 }
 
 /**
diff --git a/packages/grpc-js/src/xds-client.ts b/packages/grpc-js/src/xds-client.ts
index d29d29b8f..c2f987997 100644
--- a/packages/grpc-js/src/xds-client.ts
+++ b/packages/grpc-js/src/xds-client.ts
@@ -746,7 +746,7 @@ export class XdsClient {
        * recursively using an xDS load balancer for the xDS client would be
        * bad */
       'grpc.service_config',
-    ];
+    ] as const;
     for (const arg of channelArgsToRemove) {
       delete channelArgs[arg];
     }