diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index 07e2c41beec21b..2b9600f0fd6647 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -147,7 +147,7 @@ function Readable(options) {
 
   // Checking for a Stream.Duplex instance is faster here instead of inside
   // the ReadableState constructor, at least with V8 6.5
-  const isDuplex = (this instanceof Stream.Duplex);
+  const isDuplex = this instanceof Stream.Duplex;
 
   this._readableState = new ReadableState(options, this, isDuplex);