diff --git a/src/DeepCopySerializer.php b/src/DeepCopySerializer.php
index eba2783..d2e6f1c 100644
--- a/src/DeepCopySerializer.php
+++ b/src/DeepCopySerializer.php
@@ -25,11 +25,9 @@ class DeepCopySerializer extends Serializer
     protected function serializeObject($value)
     {
         if ($this->objectStorage->contains($value)) {
-            return [self::CLASS_IDENTIFIER_KEY => $this->objectStorage[$value]];
+            return $this->objectStorage[$value];
         }
 
-        $this->objectStorage->attach($value, $this->objectMappingIndex++);
-
         $reflection = new ReflectionClass($value);
         $className = $reflection->getName();
 
@@ -39,4 +37,4 @@ protected function serializeObject($value)
         return $serialized;
     }
 
-} 
\ No newline at end of file
+}