diff --git a/src/Updater.php b/src/Updater.php
index fcd251a5e0533f651d7b7af4c1e52546e4581e3a..dea5894d52af167de8d3e280995b4618203d9661 100644
--- a/src/Updater.php
+++ b/src/Updater.php
@@ -200,7 +200,7 @@ class Updater {
    * @return string[]
    *   The paths to exclude, relative to the active directory.
    */
-  private function getExclusions($event): array {
+  private function getExclusions(UpdateEvent $event): array {
     $make_relative = function (string $path): string {
       return str_replace($this->pathLocator->getActiveDirectory() . '/', '', $path);
     };