diff --git a/src/metadata/service.ts b/src/metadata/service.ts
index 0067fff..d7368b6 100644
--- a/src/metadata/service.ts
+++ b/src/metadata/service.ts
@@ -1,6 +1,7 @@
 import type { HttpClient, QueryParamValue } from "../http.js";
 import {
   createNamespaceService,
+  type NamespaceService,
   type OperationCall,
 } from "../service.js";
 import type { JsonObject } from "../types.js";
@@ -49,13 +50,16 @@ export interface MetadataService {
 
 export function createMetadataService(http: HttpClient): MetadataService {
   const base = createNamespaceService(http, "metadata");
+  const invoke = base as NamespaceService;
+
   const service = base as MetadataService;
 
   service.listEntities = () =>
-    base.listEntities(undefined, undefined) as Promise<ListEntitiesResult>;
+    invoke("ListEntities", undefined, undefined) as Promise<ListEntitiesResult>;
 
   service.describeMetadata = (params?: DescribeMetadataParams) =>
-    base.describeMetadata(
+    invoke(
+      "DescribeMetadata",
       undefined,
       describeMetadataQuery(params),
     ) as Promise<DescribeMetadataResult>;