diff --git a/lib/Doctrine/ORM/PersistentCollection.php b/lib/Doctrine/ORM/PersistentCollection.php
index 83eab8cf1..c2e11dfbe 100644
--- a/lib/Doctrine/ORM/PersistentCollection.php
+++ b/lib/Doctrine/ORM/PersistentCollection.php
@@ -536,6 +536,8 @@ final class PersistentCollection extends AbstractLazyCollection implements Selec
     public function clear()
     {
         if ($this->initialized && $this->isEmpty()) {
+            $this->collection->clear();
+
             return;
         }
 
diff --git a/tests/Doctrine/Tests/ORM/PersistentCollectionTest.php b/tests/Doctrine/Tests/ORM/PersistentCollectionTest.php
index e77f898d1..190fe2ef1 100644
--- a/tests/Doctrine/Tests/ORM/PersistentCollectionTest.php
+++ b/tests/Doctrine/Tests/ORM/PersistentCollectionTest.php
@@ -3,7 +3,6 @@
 namespace Doctrine\Tests\ORM;
 
 use Doctrine\Common\Collections\ArrayCollection;
-use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\PersistentCollection;
 use Doctrine\Tests\Mocks\ConnectionMock;
 use Doctrine\Tests\Mocks\DriverMock;
@@ -83,4 +82,44 @@ class PersistentCollectionTest extends OrmTestCase
         $this->collection->next();
         $this->assertTrue($this->collection->isInitialized());
     }
+
+    /**
+     * @group 6110
+     */
+    public function testRemovingElementsAlsoRemovesKeys()
+    {
+        $this->setUpPersistentCollection();
+
+        $this->collection->add('dummy');
+        $this->assertEquals([0], array_keys($this->collection->toArray()));
+
+        $this->collection->removeElement('dummy');
+        $this->assertEquals([], array_keys($this->collection->toArray()));
+    }
+
+    /**
+     * @group 6110
+     */
+    public function testClearWillAlsoClearKeys()
+    {
+        $this->setUpPersistentCollection();
+
+        $this->collection->add('dummy');
+        $this->collection->clear();
+        $this->assertEquals([], array_keys($this->collection->toArray()));
+    }
+
+    /**
+     * @group 6110
+     */
+    public function testClearWillAlsoResetKeyPositions()
+    {
+        $this->setUpPersistentCollection();
+
+        $this->collection->add('dummy');
+        $this->collection->removeElement('dummy');
+        $this->collection->clear();
+        $this->collection->add('dummy');
+        $this->assertEquals([0], array_keys($this->collection->toArray()));
+    }
 }