diff --git a/src/Subscriber.ts b/src/Subscriber.ts
index 808ad6f7c2..68a50d8add 100644
--- a/src/Subscriber.ts
+++ b/src/Subscriber.ts
@@ -6,8 +6,8 @@ import Observer from './Observer';
 import Subscription from './Subscription';
 
 export default class Subscriber<T> extends Subscription<T> implements Observer<T> {
-  private _subscription: Subscription<T>;
-  private _isUnsubscribed: boolean = false;
+  protected _subscription: Subscription<T>;
+  protected _isUnsubscribed: boolean = false;
 
   get isUnsubscribed(): boolean {
     const subscription = this._subscription;
@@ -73,9 +73,9 @@ export default class Subscriber<T> extends Subscription<T> implements Observer<T
   }
 
   unsubscribe(): void {
-    if(this._isUnsubscribed) {
+    if (this._isUnsubscribed) {
       return;
-    } else if(this._subscription) {
+    } else if (this._subscription) {
       this._isUnsubscribed = true;
     } else {
       super.unsubscribe();
diff --git a/src/operators/skipUntil.ts b/src/operators/skipUntil.ts
index ad283f7894..ca600fbd56 100644
--- a/src/operators/skipUntil.ts
+++ b/src/operators/skipUntil.ts
@@ -18,9 +18,9 @@ class SkipUntilOperator<T, R> implements Operator<T, R> {
 class SkipUntilSubscriber<T> extends Subscriber<T> {
   private notificationSubscriber: NotificationSubscriber<any> = null;
 
-  constructor(public destination: Subscriber<T>,
+  constructor(destination: Subscriber<T>,
               private notifier: Observable<any>) {
-    super(null);
+    super(destination);
     this.notificationSubscriber = new NotificationSubscriber(this);
     this.add(this.notifier.subscribe(this.notificationSubscriber));
   }
@@ -41,6 +41,17 @@ class SkipUntilSubscriber<T> extends Subscriber<T> {
     }
     this.notificationSubscriber.unsubscribe();
   }
+
+  unsubscribe() {
+    if (this._isUnsubscribed) {
+      return;
+    } else if (this._subscription) {
+      this._subscription.unsubscribe();
+      this._isUnsubscribed = true;
+    } else {
+      super.unsubscribe();
+    }
+  }
 }
 
 class NotificationSubscriber<T> extends Subscriber<T> {