diff --git a/Extension/HttpFoundation/HttpFoundationRequestHandler.php b/Extension/HttpFoundation/HttpFoundationRequestHandler.php
index 368a5a80a1..571db0eb41 100644
--- a/Extension/HttpFoundation/HttpFoundationRequestHandler.php
+++ b/Extension/HttpFoundation/HttpFoundationRequestHandler.php
@@ -108,6 +108,9 @@ public function handleRequest(FormInterface $form, $request = null)
         $form->submit($data, 'PATCH' !== $method);
     }
 
+    /**
+     * {@inheritdoc}
+     */
     public function isFileUpload($data)
     {
         return $data instanceof File;
diff --git a/NativeRequestHandler.php b/NativeRequestHandler.php
index f68efe25cf..37e1c99a74 100644
--- a/NativeRequestHandler.php
+++ b/NativeRequestHandler.php
@@ -118,6 +118,9 @@ public function handleRequest(FormInterface $form, $request = null)
         $form->submit($data, 'PATCH' !== $method);
     }
 
+    /**
+     * {@inheritdoc}
+     */
     public function isFileUpload($data)
     {
         // POST data will always be strings or arrays of strings. Thus, we can be sure
diff --git a/RequestHandlerInterface.php b/RequestHandlerInterface.php
index e6360e4498..3d7b45d506 100644
--- a/RequestHandlerInterface.php
+++ b/RequestHandlerInterface.php
@@ -27,7 +27,9 @@ interface RequestHandlerInterface
     public function handleRequest(FormInterface $form, $request = null);
 
     /**
-     * @param mixed $data
+     * Returns true if the given data is a file upload.
+     *
+     * @param mixed $data The form field data
      *
      * @return bool
      */