diff --git a/lib/_stream_duplex.js b/lib/_stream_duplex.js
index b123cdcb4d776f..7059757dbd44b1 100644
--- a/lib/_stream_duplex.js
+++ b/lib/_stream_duplex.js
@@ -50,17 +50,19 @@ function Duplex(options) {
 
   Readable.call(this, options);
   Writable.call(this, options);
+  this.allowHalfOpen = true;
 
-  if (options && options.readable === false)
-    this.readable = false;
+  if (options) {
+    if (options.readable === false)
+      this.readable = false;
 
-  if (options && options.writable === false)
-    this.writable = false;
+    if (options.writable === false)
+      this.writable = false;
 
-  this.allowHalfOpen = true;
-  if (options && options.allowHalfOpen === false) {
-    this.allowHalfOpen = false;
-    this.once('end', onend);
+    if (options.allowHalfOpen === false) {
+      this.allowHalfOpen = false;
+      this.once('end', onend);
+    }
   }
 }