diff --git a/core/lib/Drupal/Core/Config/Schema/Dictionary.php b/core/lib/Drupal/Core/Config/Schema/Dictionary.php
new file mode 100644
index 0000000..41ddc3a
--- /dev/null
+++ b/core/lib/Drupal/Core/Config/Schema/Dictionary.php
@@ -0,0 +1,30 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Config\Schema\Dictionary.
+ */
+
+namespace Drupal\Core\Config\Schema;
+
+/**
+ * Defines a configuration element of type Dictionary.
+ */
+class Dictionary extends Sequence {
+
+  /**
+   * Implements Drupal\Core\TypedData\ListInterface::getItemDefinition().
+   */
+  public function getItemDefinition() {
+    return $this->definition['dictionary'][0];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function first() {
+    $elements = $this->getElements();
+    return reset($elements);
+  }
+
+}