diff --git a/test/types/writable-stream.ts b/test/types/writable-stream.ts
index 351f87e..f29fe24 100644
--- a/test/types/writable-stream.ts
+++ b/test/types/writable-stream.ts
@@ -47,7 +47,7 @@ declare global {
   }
 }
 
-// const domUnderlyingSink: UnderlyingSink<string> = underlyingSink;
+const domUnderlyingSink: UnderlyingSink<string> = underlyingSink;
 const domWritableStream: WritableStream<string> = writableStream;
-// const domController: WritableStreamDefaultController = controller;
+const domController: WritableStreamDefaultController = controller;
 const domWriter: WritableStreamDefaultWriter<string> = writer;