diff --git a/packages/addon-kit/docs/tabs.md b/packages/addon-kit/docs/tabs.md
index ae0a29c83..66f268238 100644
--- a/packages/addon-kit/docs/tabs.md
+++ b/packages/addon-kit/docs/tabs.md
@@ -36,7 +36,8 @@ be correct at this point. Use `ready` event listener to be notified when the
 page has loaded.
 
 ### close ###
-Event emitted when a tab is closed.
+Event emitted when a tab is closed. In addition, when a window is closed,
+this event will be emitted for each of the open tabs in that window.
 
 ### ready ###
 Event emitted when a tab's content's DOM is ready.
diff --git a/packages/addon-kit/lib/windows.js b/packages/addon-kit/lib/windows.js
index cb5bea759..0f82536ba 100644
--- a/packages/addon-kit/lib/windows.js
+++ b/packages/addon-kit/lib/windows.js
@@ -113,7 +113,6 @@ const BrowserWindowTrait = Trait.compose(
       this._emitOnObject(browserWindows, 'open', this._public);
     },
     _onUnload: function() {
-      // Need to remove all the tabs before window listener are notified.
       this._destroyWindowTabTracker();
       this._emitOnObject(browserWindows, 'close', this._public);
       this._window = null;
diff --git a/packages/addon-kit/tests/test-tabs.js b/packages/addon-kit/tests/test-tabs.js
index 8e8c4c6a2..4aafd5f19 100644
--- a/packages/addon-kit/tests/test-tabs.js
+++ b/packages/addon-kit/tests/test-tabs.js
@@ -380,6 +380,61 @@ exports.testTabsEvent_onClose = function(test) {
   });
 };
 
+// onClose event handler when a window is closed
+exports.testTabsEvent_onCloseWindow = function(test) {
+  test.waitUntilDone();
+
+  openBrowserWindow(function(window, browser) {
+    var tabs = require("tabs");
+
+    let closeCount = 0, individualCloseCount = 0;
+    function listener() {
+      closeCount++;
+    }
+    tabs.on('close', listener);
+
+    // One tab is already open with the window
+    let openTabs = 1;
+    function testCasePossiblyLoaded() {
+      if (++openTabs == 4) {
+        beginCloseWindow();
+      }
+    }
+
+    tabs.open({
+      url: "data:text/html,tab2",
+      onOpen: function() testCasePossiblyLoaded(),
+      onClose: function() individualCloseCount++
+    });
+
+    tabs.open({
+      url: "data:text/html,tab3",
+      onOpen: function() testCasePossiblyLoaded(),
+      onClose: function() individualCloseCount++
+    });
+
+    tabs.open({
+      url: "data:text/html,tab4",
+      onOpen: function() testCasePossiblyLoaded(),
+      onClose: function() individualCloseCount++
+    });
+
+    function beginCloseWindow() {
+      closeBrowserWindow(window, function testFinished() {
+        tabs.removeListener("close", listener);
+
+        test.assertEqual(closeCount, 4, "Correct number of close events received");
+        test.assertEqual(individualCloseCount, 3,
+                         "Each tab with an attached onClose listener received a close " +
+                         "event when the window was closed");
+
+        test.done();
+      });
+    }
+
+  });
+}
+
 // onReady event handler
 exports.testTabsEvent_onReady = function(test) {
   test.waitUntilDone();
diff --git a/packages/api-utils/lib/list.js b/packages/api-utils/lib/list.js
index 3beff2ede..e5ccecdf0 100644
--- a/packages/api-utils/lib/list.js
+++ b/packages/api-utils/lib/list.js
@@ -138,7 +138,7 @@ const List = Trait.resolve({ toString: null }).compose({
    * @param {Boolean} onKeys
    */
   __iterator__: function __iterator__(onKeys, onKeyValue) {
-    let array = this._keyValueMap,
+    let array = this._keyValueMap.slice(0),
         i = -1;
     for each(let element in array)
       yield onKeyValue ? [++i, element] : onKeys ? ++i : element;
diff --git a/packages/api-utils/lib/windows/tabs.js b/packages/api-utils/lib/windows/tabs.js
index 80bb2f80c..f0bc1e8af 100644
--- a/packages/api-utils/lib/windows/tabs.js
+++ b/packages/api-utils/lib/windows/tabs.js
@@ -93,8 +93,8 @@ const WindowTabTracker = Trait.compose({
     }
   },
   _destroyWindowTabTracker: function _destroyWindowTabTracker() {
-    for each (tab in this.tabs)
-      tab.close();
+    for each (let tab in this.tabs)
+      this._emitEvent(EVENTS.close, tab);
     this._tabs._clear();
   },
   /**
diff --git a/packages/api-utils/tests/test-list.js b/packages/api-utils/tests/test-list.js
index 7a1c98621..3190fe7d7 100644
--- a/packages/api-utils/tests/test-list.js
+++ b/packages/api-utils/tests/test-list.js
@@ -144,3 +144,51 @@ exports['test:removing adding elements'] = function(test) {
   assertList(test, array, fixture);
 };
 
+exports['test:add list item from Iterator'] = function(test) {
+  let array = [1, 2, 3, 4], sum = 0, added = false;
+
+  let fixture = List.compose({
+    add: function() this._add.apply(this, arguments),
+  }).apply(null, array);
+
+  for each (let item in fixture) {
+    sum += item;
+
+    if (!added) {
+      fixture.add(5);
+      added = true;
+    }
+  }
+
+  test.assertEqual(sum, 1 + 2 + 3 + 4);
+};
+
+exports['test:remove list item from Iterator'] = function(test) {
+  let array = [1, 2, 3, 4], sum = 0;
+
+  let fixture = List.compose({
+    remove: function() this._remove.apply(this, arguments),
+  }).apply(null, array);
+
+  for each (let item in fixture) {
+    sum += item;
+    fixture.remove(item);
+  }
+
+  test.assertEqual(sum, 1 + 2 + 3 + 4);
+};
+
+exports['test:clear list from Iterator'] = function(test) {
+  let array = [1, 2, 3, 4], sum = 0;
+
+  let fixture = List.compose({
+    clear: function() this._clear()
+  }).apply(null, array);
+
+  for each (let item in fixture) {
+    sum += item;
+    fixture.clear();
+  }
+
+  test.assertEqual(sum, 1 + 2 + 3 + 4);
+};