diff --git a/laravel/database/eloquent/model.php b/laravel/database/eloquent/model.php
index 05fef675..8703f4c4 100644
--- a/laravel/database/eloquent/model.php
+++ b/laravel/database/eloquent/model.php
@@ -538,7 +538,7 @@ public function get_dirty()
 
 		foreach ($this->attributes as $key => $value)
 		{
-			if ( ! isset($this->original[$key]) or $value !== $this->original[$key])
+			if ( ! array_key_exists($key, $this->original) or $value !== $this->original[$key])
 			{
 				$dirty[$key] = $value;
 			}