1 files changed, 13 insertions, 3 deletions
diff --git a/lib/_stream_duplex.js b/lib/_stream_duplex.js
index d20877e921..b96a0439f7 100644
--- a/lib/_stream_duplex.js
+++ b/lib/_stream_duplex.js
@@ -74,7 +74,7 @@ Object.defineProperty(Duplex.prototype, 'writableHighWaterMark', {
   // userland will fail
   enumerable: false,
   get() {
-    return this._writableState.highWaterMark;
+    return this._writableState && this._writableState.highWaterMark;
   }
 });
 
@@ -94,7 +94,7 @@ Object.defineProperty(Duplex.prototype, 'writableLength', {
   // userland will fail
   enumerable: false,
   get() {
-    return this._writableState.length;
+    return this._writableState && this._writableState.length;
   }
 });
 
@@ -104,7 +104,17 @@ Object.defineProperty(Duplex.prototype, 'writableFinished', {
   // userland will fail
   enumerable: false,
   get() {
-    return this._writableState.finished;
+    return this._writableState ? this._writableState.finished : false;
+  }
+});
+
+Object.defineProperty(Duplex.prototype, 'writableEnded', {
+  // Making it explicit this property is not enumerable
+  // because otherwise some prototype manipulation in
+  // userland will fail
+  enumerable: false,
+  get() {
+    return this._writableState ? this._writableState.ending : false;
   }
 });