diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index f414d53..1f8fdaf 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -420,7 +420,7 @@ function config_get_config_directory($type = CONFIG_ACTIVE_DIRECTORY) {
   if (!empty($config_directories[$type])) {
     // Allow a configuration directory path to be outside of webroot.
     if (empty($config_directories[$type]['absolute'])) {
-      $path = conf_path() . '/files/' . $config_directories[$type]['path'];
+      $path = DRUPAL_ROOT . '/' . conf_path() . '/files/' . $config_directories[$type]['path'];
     }
     else {
       $path = $config_directories[$type]['path'];
diff --git a/core/includes/config.inc b/core/includes/config.inc
index 8e9ce5e..0b894c6 100644
--- a/core/includes/config.inc
+++ b/core/includes/config.inc
@@ -44,7 +44,7 @@ function config_install_default_config($type, $name) {
 
   // Work out if this extension provides default configuration for any other
   // enabled extensions.
-  $config_dir = drupal_get_path($type, $name) . '/config';
+  $config_dir = DRUPAL_ROOT . '/' . drupal_get_path($type, $name) . '/config';
   if (is_dir($config_dir)) {
     $default_storage = new FileStorage($config_dir);
     $other_module_config = array_filter($default_storage->listAll(),
diff --git a/core/lib/Drupal/Core/Config/InstallStorage.php b/core/lib/Drupal/Core/Config/InstallStorage.php
index 20d20fc..aa2b3ea 100644
--- a/core/lib/Drupal/Core/Config/InstallStorage.php
+++ b/core/lib/Drupal/Core/Config/InstallStorage.php
@@ -155,7 +155,7 @@ public function getComponentNames($type, array $list) {
    *   The configuration folder name for this component.
    */
   protected function getComponentFolder($type, $name) {
-    return drupal_get_path($type, $name) . '/config';
+    return DRUPAL_ROOT . '/' . drupal_get_path($type, $name) . '/config';
   }
 
   /**