diff --git a/src/Symfony/Component/Routing/Route.php b/src/Symfony/Component/Routing/Route.php
index 8e5576bd26..28966945d6 100644
--- a/src/Symfony/Component/Routing/Route.php
+++ b/src/Symfony/Component/Routing/Route.php
@@ -61,6 +61,9 @@ class Route implements \Serializable
      */
     private $compiled;
 
+    /**
+     * @var string
+     */
     private $condition;
 
     /**
@@ -130,8 +133,10 @@ class Route implements \Serializable
         $this->options = $data['options'];
         $this->schemes = $data['schemes'];
         $this->methods = $data['methods'];
-        $this->condition = $data['condition'];
 
+        if (isset($data['condition'])) {
+            $this->condition = $data['condition'];
+        }
         if (isset($data['compiled'])) {
             $this->compiled = $data['compiled'];
         }