diff --git a/src/Illuminate/Queue/SerializesModels.php b/src/Illuminate/Queue/SerializesModels.php
index 15c4af3c4918..e083d6f3217a 100644
--- a/src/Illuminate/Queue/SerializesModels.php
+++ b/src/Illuminate/Queue/SerializesModels.php
@@ -24,9 +24,9 @@ public function __sleep()
             ));
         }
 
-        return array_filter(array_map(function ($p) {
+        return array_values(array_filter(array_map(function ($p) {
             return $p->isStatic() ? null : $p->getName();
-        }, $properties));
+        }, $properties)));
     }
 
     /**