diff --git a/code/Forms/FileHistoryFormFactory.php b/code/Forms/FileHistoryFormFactory.php
index 1167ed086..100f3d8cc 100644
--- a/code/Forms/FileHistoryFormFactory.php
+++ b/code/Forms/FileHistoryFormFactory.php
@@ -47,7 +47,7 @@ protected function getSpecsMarkup($record)
         );
     }
 
-    protected function getFormFields(?RequestHandler $controller = null, $name, $context = [])
+    protected function getFormFields(?RequestHandler $controller, $name, $context = [])
     {
         $record = $context['Record'];
 
diff --git a/code/Forms/FileSearchFormFactory.php b/code/Forms/FileSearchFormFactory.php
index abecaeb71..4ce8c2791 100644
--- a/code/Forms/FileSearchFormFactory.php
+++ b/code/Forms/FileSearchFormFactory.php
@@ -49,7 +49,7 @@ public function getForm(?RequestHandler $controller = null, $name = FormFactory:
      * @param array $context
      * @return FieldList
      */
-    protected function getFormFields(?RequestHandler $controller = null, $name, $context = [])
+    protected function getFormFields(?RequestHandler $controller, $name, $context = [])
     {
         // Note: "Name" field is excluded as it is baked directly into the Search.js react component
 
diff --git a/code/Forms/FolderCreateFormFactory.php b/code/Forms/FolderCreateFormFactory.php
index ac8d15a88..3e29e8911 100644
--- a/code/Forms/FolderCreateFormFactory.php
+++ b/code/Forms/FolderCreateFormFactory.php
@@ -16,7 +16,7 @@ public function getRequiredContext()
         return ['ParentID'];
     }
 
-    public function getFormFields(?RequestHandler $controller = null, $name, $context = [])
+    public function getFormFields(?RequestHandler $controller, $name, $context = [])
     {
         // Add status flag before extensions are triggered
         $this->beforeExtending('updateFormFields', function (FieldList $fields) use ($context) {
diff --git a/code/Forms/FolderFormFactory.php b/code/Forms/FolderFormFactory.php
index afa290c70..6421df6c9 100644
--- a/code/Forms/FolderFormFactory.php
+++ b/code/Forms/FolderFormFactory.php
@@ -13,7 +13,7 @@
 class FolderFormFactory extends AssetFormFactory
 {
 
-    protected function getFormFields(?RequestHandler $controller = null, $name, $context = [])
+    protected function getFormFields(?RequestHandler $controller, $name, $context = [])
     {
         /** @var Folder $record */
         $record = $context['Record'] ?? null;