diff --git a/README.md b/README.md
index 642d3de6be..6cc8fd3c62 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ By contributing or commenting on issues in this repository, whether you've read
 ### ES6 via npm
 
 ```sh
-npm install rxjs-es
+npm install rxjs
 ```
 
 To import the entire core set of functionality:
diff --git a/package.json b/package.json
index 100adc509d..66252b7102 100644
--- a/package.json
+++ b/package.json
@@ -70,10 +70,10 @@
     "copy_src_cjs": "mkdirp ./dist/cjs/src && shx cp -r ./src/* ./dist/cjs/src",
     "copy_src_es6": "mkdirp ./dist/es6/src && shx cp -r ./src/* ./dist/es6/src",
     "commit": "git-cz",
-    "compile_dist_cjs": "tsc typings/globals/es6-shim/index.d.ts ./dist/cjs/src/Rx.ts ./dist/cjs/src/add/observable/of.ts                             -m commonjs --sourceMap --outDir ./dist/cjs --target ES5 -d --diagnostics --pretty --noImplicitAny --noImplicitReturns --suppressImplicitAnyIndexErrors --moduleResolution node",
+    "compile_dist_cjs": "tsc ./dist/cjs/src/Rx.ts ./dist/cjs/src/add/observable/of.ts                         -m commonjs --lib es5,es2015.iterable,es2015.collection,es2015.promise,dom --sourceMap --outDir ./dist/cjs --target ES5 -d --diagnostics --pretty --noImplicitAny --noImplicitReturns --suppressImplicitAnyIndexErrors --moduleResolution node",
     "compile_dist_es6": "tsc                                          ./dist/es6/src/Rx.ts ./dist/es6/src/add/observable/of.ts                             -m es2015   --sourceMap --outDir ./dist/es6 --target ES6 -d --diagnostics --pretty --noImplicitAny --noImplicitReturns --suppressImplicitAnyIndexErrors --moduleResolution node",
     "compile_dist_es6_for_docs": "tsc                                 ./dist/es6/src/Rx.ts ./dist/es6/src/add/observable/of.ts ./dist/es6/src/MiscJSDoc.ts -m es2015   --sourceMap --outDir ./dist/es6 --target ES6 -d --diagnostics --pretty --noImplicitAny --noImplicitReturns --suppressImplicitAnyIndexErrors --moduleResolution node",
-    "cover": "shx rm -rf dist/cjs && tsc typings/globals/es6-shim/index.d.ts src/Rx.ts src/add/observable/of.ts -m commonjs --outDir dist/cjs --sourceMap --target ES5 -d && nyc --reporter=lcov --reporter=html --exclude=spec/support/**/* --exclude=spec-js/**/* --exclude=node_modules mocha --opts spec/support/default.opts spec-js",
+    "cover": "shx rm -rf dist/cjs && tsc src/Rx.ts src/add/observable/of.ts -m commonjs --lib es5,es2015.iterable,es2015.collection,es2015.promise,dom --outDir dist/cjs --sourceMap --target ES5 -d && nyc --reporter=lcov --reporter=html --exclude=spec/support/**/* --exclude=spec-js/**/* --exclude=node_modules mocha --opts spec/support/default.opts spec-js",
     "decision_tree_widget": "cd doc/decision-tree-widget && npm run build && cd ../..",
     "doctoc": "doctoc CONTRIBUTING.md",
     "generate_packages": "node .make-packages.js",
diff --git a/spec/observables/IteratorObservable-spec.ts b/spec/observables/IteratorObservable-spec.ts
index 3149f213a2..63b1d73761 100644
--- a/spec/observables/IteratorObservable-spec.ts
+++ b/spec/observables/IteratorObservable-spec.ts
@@ -1,5 +1,6 @@
 import {expect} from 'chai';
 import * as Rx from '../../dist/cjs/Rx';
+import {queue} from '../../dist/cjs/scheduler/queue';
 import {IteratorObservable} from '../../dist/cjs/observable/IteratorObservable';
 
 declare const expectObservable;
@@ -46,6 +47,68 @@ describe('IteratorObservable', () => {
       );
   });
 
+  it('should finalize generators if the subscription ends', () => {
+    const iterator = {
+      finalized: false,
+      next() {
+        return { value: 'duck', done: false };
+      },
+      return() {
+        this.finalized = true;
+      }
+    };
+
+    const iterable = {
+      [Rx.Symbol.iterator]() {
+        return iterator;
+      }
+    };
+
+    const results = [];
+
+    IteratorObservable.create(iterable)
+      .take(3)
+      .subscribe(
+        x => results.push(x),
+        null,
+        () => results.push('GOOSE!')
+      );
+
+    expect(results).to.deep.equal(['duck', 'duck', 'duck', 'GOOSE!']);
+    expect(iterator.finalized).to.be.true;
+  });
+
+  it('should finalize generators if the subscription and it is scheduled', () => {
+    const iterator = {
+      finalized: false,
+      next() {
+        return { value: 'duck', done: false };
+      },
+      return() {
+        this.finalized = true;
+      }
+    };
+
+    const iterable = {
+      [Rx.Symbol.iterator]() {
+        return iterator;
+      }
+    };
+
+    const results = [];
+
+    IteratorObservable.create(iterable, queue)
+      .take(3)
+      .subscribe(
+        x => results.push(x),
+        null,
+        () => results.push('GOOSE!')
+      );
+
+    expect(results).to.deep.equal(['duck', 'duck', 'duck', 'GOOSE!']);
+    expect(iterator.finalized).to.be.true;
+  });
+
   it('should emit members of an array iterator on a particular scheduler', () => {
     const source = IteratorObservable.create(
       [10, 20, 30, 40],
diff --git a/spec/tsconfig.json b/spec/tsconfig.json
index 182a705625..bb3d0fb553 100644
--- a/spec/tsconfig.json
+++ b/spec/tsconfig.json
@@ -7,7 +7,15 @@
         "allowJs": true,
         "target": "es5",
         "module": "commonjs",
-        "outDir": "../spec-js"
+        "outDir": "../spec-js",
+        "lib": [
+            "es5",
+            "es2015.core",
+            "es2015.collection",
+            "es2015.iterable",
+            "es2015.promise",
+            "dom"
+        ]
     },
     "formatCodeOptions": {
         "indentSize": 2,
diff --git a/src/Subject.ts b/src/Subject.ts
index dcea18e734..b3dacf0d80 100644
--- a/src/Subject.ts
+++ b/src/Subject.ts
@@ -43,9 +43,9 @@ export class Subject<T> extends Observable<T> implements ISubscription {
     return new AnonymousSubject<T>(destination, source);
   };
 
-  lift<T, R>(operator: Operator<T, R>): Observable<T> {
+  lift<R>(operator: Operator<T, R>): Observable<T> {
     const subject = new AnonymousSubject(this, this);
-    subject.operator = operator;
+    subject.operator = <any>operator;
     return <any>subject;
   }
 
diff --git a/src/observable/IteratorObservable.ts b/src/observable/IteratorObservable.ts
index 4195965f25..586afc6ad3 100644
--- a/src/observable/IteratorObservable.ts
+++ b/src/observable/IteratorObservable.ts
@@ -36,6 +36,9 @@ export class IteratorObservable<T> extends Observable<T> {
     state.index = index + 1;
 
     if (subscriber.closed) {
+      if (typeof iterator.return === 'function') {
+        iterator.return();
+      }
       return;
     }
 
@@ -71,6 +74,9 @@ export class IteratorObservable<T> extends Observable<T> {
           subscriber.next(result.value);
         }
         if (subscriber.closed) {
+          if (typeof iterator.return === 'function') {
+            iterator.return();
+          }
           break;
         }
       } while (true);
diff --git a/typings.json b/typings.json
index 62dc7f0eaf..fdf5194f8c 100644
--- a/typings.json
+++ b/typings.json
@@ -7,9 +7,6 @@
     "sinon-chai": "registry:npm/sinon-chai#2.8.0+20160310030142"
   },
   "globalDevDependencies": {
-    "mocha": "registry:env/mocha#2.2.5+20160723033700"
-  },
-  "globalDependencies": {
-    "es6-shim": "registry:dt/es6-shim#0.31.2+20160602141504"
+    "mocha": "registry:env/mocha#2.2.5+20160926180742"
   }
 }