diff --git a/code/Controllers/CMSPageEditController.php b/code/Controllers/CMSPageEditController.php
index 2bd91981..67dcfb38 100644
--- a/code/Controllers/CMSPageEditController.php
+++ b/code/Controllers/CMSPageEditController.php
@@ -34,7 +34,7 @@ class CMSPageEditController extends CMSMain
         'AddToCampaignForm',
     ];
 
-    public function getClientConfig()
+    public function getClientConfig(): array
     {
         return ArrayLib::array_merge_recursive(parent::getClientConfig(), [
             'form' => [