diff --git a/lib/Doctrine/ODM/MongoDB/Hydrator.php b/lib/Doctrine/ODM/MongoDB/Hydrator.php
index 2d526127b0..6dd8502424 100644
--- a/lib/Doctrine/ODM/MongoDB/Hydrator.php
+++ b/lib/Doctrine/ODM/MongoDB/Hydrator.php
@@ -104,6 +104,8 @@ public function hydrate($document, &$data)
         // Set the document identifier
         if (isset($data['_id'])) {
             $metadata->setIdentifierValue($document, $data['_id']);
+            $data[$metadata->identifier] = $data['_id'];
+            unset($data['_id']);
         }
         return $document;
     }
diff --git a/lib/Doctrine/ODM/MongoDB/UnitOfWork.php b/lib/Doctrine/ODM/MongoDB/UnitOfWork.php
index 0a9603d656..f621a0aed1 100644
--- a/lib/Doctrine/ODM/MongoDB/UnitOfWork.php
+++ b/lib/Doctrine/ODM/MongoDB/UnitOfWork.php
@@ -385,8 +385,7 @@ public function computeChangeSet(Mapping\ClassMetadata $class, $document)
                 $coll->setDirty( ! $coll->isEmpty());
                 $class->reflFields[$name]->setValue($document, $coll);
                 $actualData[$name] = $coll;
-            }
-            if ($class->isCollectionValuedEmbed($name) && $actualData[$name] !== null
+            } elseif ($class->isCollectionValuedEmbed($name) && $actualData[$name] !== null
                     && ! ($actualData[$name] instanceof Collection)) {
                 // If $actualData[$name] is not a Collection then use an ArrayCollection.
                 if ( ! $actualData[$name] instanceof Collection) {