diff --git a/core/modules/file/src/Plugin/Field/FieldType/FileItem.php b/core/modules/file/src/Plugin/Field/FieldType/FileItem.php
index f609b70..7722e66 100644
--- a/core/modules/file/src/Plugin/Field/FieldType/FileItem.php
+++ b/core/modules/file/src/Plugin/Field/FieldType/FileItem.php
@@ -309,8 +309,12 @@ public static function generateSampleValue(FieldDefinitionInterface $field_defin
     $random = new Random();
     $settings = $field_definition->getSettings();
 
+    // Prepare destination.
+    $dirname = $settings['uri_scheme'] . '://' . $settings['file_directory'];
+    file_prepare_directory($dirname, FILE_CREATE_DIRECTORY);
+
     // Generate a file entity.
-    $destination = $settings['uri_scheme'] . '://' . $settings['file_directory'] . $random->name(10, TRUE) . '.txt';
+    $destination = $dirname . '/' . $random->name(10, TRUE) . '.txt';
     $data = $random->paragraphs(3);
     $file = file_save_data($data, $destination, FILE_EXISTS_ERROR);
     $values = array(
diff --git a/core/modules/file/src/Tests/FileItemTest.php b/core/modules/file/src/Tests/FileItemTest.php
index 140b00c..1275023 100644
--- a/core/modules/file/src/Tests/FileItemTest.php
+++ b/core/modules/file/src/Tests/FileItemTest.php
@@ -49,6 +49,7 @@ protected function setUp() {
       'entity_type' => 'entity_test',
       'field_name' => 'file_test',
       'bundle' => 'entity_test',
+      'settings' => array('file_directory' => $this->getRandomGenerator()->name(8)),
     ))->save();
     file_put_contents('public://example.txt', $this->randomMachineName());
     $this->file = entity_create('file', array(