diff --git a/src/Controller.php b/src/Controller.php
index <HASH>..<HASH> 100644
--- a/src/Controller.php
+++ b/src/Controller.php
@@ -26,7 +26,7 @@ class Controller
 	public function __construct($opts = [])
 	{
 		// Set the instance of our application
-		$this->app = $GLOBALS['app_instance'];
+		$this->app = array_key_exists('app_instance', $GLOBALS) ? $GLOBALS['app_instance'] : null;
 
 		// Where is our app's source code?
 		$app_dir = array_key_exists('app_dir', $opts) ? $opts['app_dir'] : null;
Fix uninitialized variable.