diff --git a/Doctrine/AbstractElasticaToModelTransformer.php b/Doctrine/AbstractElasticaToModelTransformer.php
index 8774106..9a74cfa 100755
--- a/Doctrine/AbstractElasticaToModelTransformer.php
+++ b/Doctrine/AbstractElasticaToModelTransformer.php
@@ -111,6 +111,14 @@ abstract class AbstractElasticaToModelTransformer implements ElasticaToModelTran
         return $result;
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getIdentifierField()
+    {
+        return $this->options['identifier'];
+    }
+
     /**
      * Fetches objects by theses identifier values
      *
diff --git a/Propel/ElasticaToModelTransformer.php b/Propel/ElasticaToModelTransformer.php
index 16499c6..824b523 100644
--- a/Propel/ElasticaToModelTransformer.php
+++ b/Propel/ElasticaToModelTransformer.php
@@ -100,6 +100,14 @@ class ElasticaToModelTransformer implements ElasticaToModelTransformerInterface
         return $this->objectClass;
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getIdentifierField()
+    {
+        return $this->options['identifier'];
+    }
+
     /**
      * Fetch objects for theses identifier values
      *
diff --git a/Resources/config/config.xml b/Resources/config/config.xml
index 95c5406..b6b9c92 100644
--- a/Resources/config/config.xml
+++ b/Resources/config/config.xml
@@ -61,7 +61,6 @@
 
         <service id="foq_elastica.elastica_to_model_transformer.collection.prototype" class="%foq_elastica.elastica_to_model_transformer.collection.class%" public="true" abstract="true">
             <argument type="collection" /> <!-- transformers -->
-            <argument type="collection" /> <!-- options -->
         </service>
 
         <service id="foq_elastica.provider_registry" class="%foq_elastica.provider_registry.class%">
diff --git a/Tests/Transformer/ElasticaToModelTransformerCollectionTest.php b/Tests/Transformer/ElasticaToModelTransformerCollectionTest.php
index e739959..05ddaaa 100644
--- a/Tests/Transformer/ElasticaToModelTransformerCollectionTest.php
+++ b/Tests/Transformer/ElasticaToModelTransformerCollectionTest.php
@@ -19,11 +19,19 @@ class ElasticaToModelTransformerCollectionTest extends \PHPUnit_Framework_TestCa
             ->method('getObjectClass')
             ->will($this->returnValue('FOQ\ElasticaBundle\Tests\Transformer\POPO'));
 
+        $transformer1->expects($this->any())
+            ->method('getIdentifierField')
+            ->will($this->returnValue('id'));
+
         $transformer2 = $this->getMock('FOQ\ElasticaBundle\Transformer\ElasticaToModelTransformerInterface');
         $transformer2->expects($this->any())
             ->method('getObjectClass')
             ->will($this->returnValue('FOQ\ElasticaBundle\Tests\Transformer\POPO2'));
 
+        $transformer2->expects($this->any())
+            ->method('getIdentifierField')
+            ->will($this->returnValue('id'));
+
         $this->collection = new ElasticaToModelTransformerCollection($this->transformers = array(
             'type1' => $transformer1,
             'type2' => $transformer2,
diff --git a/Transformer/ElasticaToModelTransformerCollection.php b/Transformer/ElasticaToModelTransformerCollection.php
index 2418e2e..539f03d 100644
--- a/Transformer/ElasticaToModelTransformerCollection.php
+++ b/Transformer/ElasticaToModelTransformerCollection.php
@@ -13,14 +13,10 @@ use Symfony\Component\Form\Util\PropertyPath;
 class ElasticaToModelTransformerCollection implements ElasticaToModelTransformerInterface
 {
     protected $transformers = array();
-    protected $options = array(
-        'identifier' => 'id'
-    );
 
-    public function __construct(array $transformers, array $options)
+    public function __construct(array $transformers)
     {
         $this->transformers = $transformers;
-        $this->options = array_merge($this->options, $options);
     }
 
     public function getObjectClass()
@@ -30,6 +26,16 @@ class ElasticaToModelTransformerCollection implements ElasticaToModelTransformer
         }, $this->transformers);
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getIdentifierField()
+    {
+        return array_map(function ($transformer) {
+            return $transformer->getIdentifierField();
+        }, $this->transformers);
+    }
+
     public function transform(array $elasticaObjects)
     {
         $sorted = array();
@@ -37,12 +43,19 @@ class ElasticaToModelTransformerCollection implements ElasticaToModelTransformer
             $sorted[$object->getType()][] = $object;
         }
 
-        $identifierProperty = new PropertyPath($this->options['identifier']);
-
         $transformed = array();
         foreach ($sorted AS $type => $objects) {
             $transformedObjects = $this->transformers[$type]->transform($objects);
-            $transformed[$type] = array_combine(array_map(function($o) use ($identifierProperty) {return $identifierProperty->getValue($o);},$transformedObjects),$transformedObjects);
+            $identifierGetter = 'get' . ucfirst($this->transformers[$type]->getIdentifierField());
+            $transformed[$type] = array_combine(
+                array_map(
+                    function($o) use ($identifierGetter) {
+                        return $o->$identifierGetter();
+                    },
+                    $transformedObjects
+                ),
+                $transformedObjects
+            );
         }
 
         $result = array();
@@ -71,4 +84,4 @@ class ElasticaToModelTransformerCollection implements ElasticaToModelTransformer
             return $transformer->getObjectClass();
         }, $this->transformers);
     }
-}
\ No newline at end of file
+}
diff --git a/Transformer/ElasticaToModelTransformerInterface.php b/Transformer/ElasticaToModelTransformerInterface.php
index 5f3f5aa..971bdfe 100644
--- a/Transformer/ElasticaToModelTransformerInterface.php
+++ b/Transformer/ElasticaToModelTransformerInterface.php
@@ -24,4 +24,11 @@ interface ElasticaToModelTransformerInterface
      * @return string
      */
     function getObjectClass();
+
+    /**
+     * Returns the identifier field from the options
+     *
+     * @return string the identifier field
+     */
+    function getIdentifierField();
 }