diff --git a/laravel/database/eloquent/model.php b/laravel/database/eloquent/model.php
index 2ad1c72b..7e9b0ba3 100644
--- a/laravel/database/eloquent/model.php
+++ b/laravel/database/eloquent/model.php
@@ -725,7 +725,7 @@ public function __isset($key)
 	{
 		foreach (array('attributes', 'relationships') as $source)
 		{
-			if (array_key_exists($key, $this->$source)) return true;
+			if (array_key_exists($key, $this->$source)) return !is_null($this->$source[$key]);
 		}
 		
 		if (method_exists($this, $key)) return true;