diff --git a/includes/CategoryManager.php b/includes/CategoryManager.php
index d08b887c..964fd33f 100644
--- a/includes/CategoryManager.php
+++ b/includes/CategoryManager.php
@@ -20,6 +20,8 @@
 
 namespace MediaWiki\Linter;
 
+use InvalidArgumentException;
+
 /**
  * Functions for lint error categories
  */