diff --git a/lib/internal/streams/duplexify.js b/lib/internal/streams/duplexify.js
index bfcd51233ac786..b591ee3fd981ff 100644
--- a/lib/internal/streams/duplexify.js
+++ b/lib/internal/streams/duplexify.js
@@ -8,6 +8,8 @@ const {
   isReadableNodeStream,
   isWritableNodeStream,
   isDuplexNodeStream,
+  isReadableStream,
+  isWritableStream,
 } = require('internal/streams/utils');
 const eos = require('internal/streams/end-of-stream');
 const {