diff --git a/code/Model/SiteTree.php b/code/Model/SiteTree.php
index 033f48dc00..c269fa4693 100755
--- a/code/Model/SiteTree.php
+++ b/code/Model/SiteTree.php
@@ -1626,7 +1626,7 @@ protected function onAfterDelete()
         parent::onAfterDelete();
     }
 
-    public function validate()
+    public function validate(): ValidationResult
     {
         $result = parent::validate();
 
diff --git a/code/Model/VirtualPage.php b/code/Model/VirtualPage.php
index 5678422b0f..b3ade3f21d 100644
--- a/code/Model/VirtualPage.php
+++ b/code/Model/VirtualPage.php
@@ -381,7 +381,7 @@ public function getSettingsFields()
         return $fields;
     }
 
-    public function validate()
+    public function validate(): ValidationResult
     {
         $result = parent::validate();