diff --git a/core/lib/Drupal/Core/Config/FileStorage.php b/core/lib/Drupal/Core/Config/FileStorage.php
index 2ac9ceeee8a6..52c9aa520db4 100644
--- a/core/lib/Drupal/Core/Config/FileStorage.php
+++ b/core/lib/Drupal/Core/Config/FileStorage.php
@@ -204,7 +204,7 @@ class FileStorage implements StorageInterface {
       throw new StorageException($this->directory . '/ not found.');
     }
     $extension = '.' . static::getFileExtension();
-    $files = new \GlobIterator($this->directory . '/' . $prefix . '*' . $extension);
+    $files = new \GlobIterator(DRUPAL_ROOT . '/' . $this->directory . '/' . $prefix . '*' . $extension);
 
     $names = array();
     foreach ($files as $file) {
diff --git a/core/lib/Drupal/Core/Config/InstallStorage.php b/core/lib/Drupal/Core/Config/InstallStorage.php
index 20d20fc50529..16bcc1c3523f 100644
--- a/core/lib/Drupal/Core/Config/InstallStorage.php
+++ b/core/lib/Drupal/Core/Config/InstallStorage.php
@@ -134,7 +134,7 @@ class InstallStorage extends FileStorage {
     foreach ($list as $name) {
       $directory = $this->getComponentFolder($type, $name);
       if (file_exists($directory)) {
-        $files = new \GlobIterator($directory . '/*' . $extension);
+        $files = new \GlobIterator(DRUPAL_ROOT . '/' . $directory . '/*' . $extension);
         foreach ($files as $file) {
           $folders[$file->getBasename($extension)] = $directory;
         }