diff --git a/src/Core/Addon.php b/src/Core/Addon.php
index c3f559c708..1ec8730534 100644
--- a/src/Core/Addon.php
+++ b/src/Core/Addon.php
@@ -84,7 +84,7 @@ class Addon extends BaseObject
 			$func();
 		}
 
-		unset(self::$addons[$idx]);
+		unset(self::$addons[array_search($addon, self::$addons)]);
 	}
 
 	/**