diff --git a/system/core/Common.php b/system/core/Common.php
index c08755c..1708653 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -240,7 +240,7 @@
 		}
 
 		// Is the config file in the environment folder?
-		if (defined(ENVIRONMENT) && file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/config.php'))
+		if (defined('ENVIRONMENT') && file_exists($file_path = APPPATH.'config/'.ENVIRONMENT.'/config.php'))
 		{
 			require($file_path);
 		}