diff -u b/core/lib/Drupal/Core/Config/Schema/SchemaStorage.php b/core/lib/Drupal/Core/Config/Schema/SchemaStorage.php
--- b/core/lib/Drupal/Core/Config/Schema/SchemaStorage.php
+++ b/core/lib/Drupal/Core/Config/Schema/SchemaStorage.php
@@ -69,16 +69,19 @@
       parent::getAllFolders();
-
-      // Ensure that the system schema are available as the base types used by
-      // all config schema are defined here. This ensures base configuration
-      // schema always exist regardless of whether or not the system.module is
-      // installed. This allows drupal_install_system() and
-      // \Drupal\simpletest\DrupalUnitTestBase to work.
-      if (!isset($this->folders['system.schema'])) {
-        $this->folders += $this->getComponentNames('module', array('system'));
-      }
-
+      $this->folders += $this->getBaseDataTypeSchema();
     }
     return $this->folders;
   }
 
+  /**
+   * Gets the base data types for configuration schema.
+   *
+   * @return array
+   *   The file containing the base data types for configuration schema.
+   */
+  protected function getBaseDataTypeSchema() {
+    return array(
+      'core.data_types.schema' => 'core/lib/Drupal/Core/Config/Schema'
+    );
+  }
+
 }