diff --git a/src/Symfony/Component/Form/Extension/Core/EventListener/ResizeFormListener.php b/src/Symfony/Component/Form/Extension/Core/EventListener/ResizeFormListener.php
index f1c39db245..207cbd3d38 100644
--- a/src/Symfony/Component/Form/Extension/Core/EventListener/ResizeFormListener.php
+++ b/src/Symfony/Component/Form/Extension/Core/EventListener/ResizeFormListener.php
@@ -139,11 +139,17 @@ class ResizeFormListener implements EventSubscriberInterface
         // The data mapper only adds, but does not remove items, so do this
         // here
         if ($this->allowDelete) {
+            $toDelete = array();
+
             foreach ($data as $name => $child) {
                 if (!$form->has($name)) {
-                    unset($data[$name]);
+                    $toDelete[] = $name;
                 }
             }
+
+            foreach ($toDelete as $name) {
+                unset($data[$name]);
+            }
         }
 
         $event->setData($data);
diff --git a/src/Symfony/Component/Form/Tests/Extension/Core/EventListener/ResizeFormListenerTest.php b/src/Symfony/Component/Form/Tests/Extension/Core/EventListener/ResizeFormListenerTest.php
index 3c162654dd..07620dc635 100644
--- a/src/Symfony/Component/Form/Tests/Extension/Core/EventListener/ResizeFormListenerTest.php
+++ b/src/Symfony/Component/Form/Tests/Extension/Core/EventListener/ResizeFormListenerTest.php
@@ -254,7 +254,20 @@ class ResizeFormListenerTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals(array(), $event->getData());
     }
 
-    public function testOnSubmitDealsWithIteratorAggregate()
+    public function testOnSubmitDealsWithObjectBackedIteratorAggregate()
+    {
+        $this->form->add($this->getForm('1'));
+
+        $data = new \ArrayObject(array(0 => 'first', 1 => 'second', 2 => 'third'));
+        $event = new FormEvent($this->form, $data);
+        $listener = new ResizeFormListener('text', array(), false, true);
+        $listener->onSubmit($event);
+
+        $this->assertArrayNotHasKey(0, $event->getData());
+        $this->assertArrayNotHasKey(2, $event->getData());
+    }
+
+    public function testOnSubmitDealsWithArrayBackedIteratorAggregate()
     {
         $this->form->add($this->getForm('1'));