diff --git a/doc/api/stream.md b/doc/api/stream.md
index bc9245d60770b3..a6f35dc9c0282a 100644
--- a/doc/api/stream.md
+++ b/doc/api/stream.md
@@ -1643,8 +1643,8 @@ class MyDuplex extends Duplex {
   _write(chunk, encoding, callback) {
     // The underlying source only deals with strings
     if (Buffer.isBuffer(chunk))
-      chunk = chunk.toString(encoding);
-    this[kSource].writeSomeData(chunk, encoding);
+      chunk = chunk.toString();
+    this[kSource].writeSomeData(chunk);
     callback();
   }