diff --git a/core/lib/Drupal/Core/Config/TypedConfigManager.php b/core/lib/Drupal/Core/Config/TypedConfigManager.php
index 42756d6..2b437c6 100644
--- a/core/lib/Drupal/Core/Config/TypedConfigManager.php
+++ b/core/lib/Drupal/Core/Config/TypedConfigManager.php
@@ -116,7 +116,7 @@ public function buildDataDefinition(array $definition, $value, $name = NULL, $pa
   /**
    * {@inheritdoc}
    */
-  public function getDefinition($base_plugin_id, $exception_on_invalid = TRUE, $is_config_name = FALSE) {
+  public function getDefinition($base_plugin_id, $exception_on_invalid = TRUE) {
     $definitions = $this->getDefinitions();
     if (isset($definitions[$base_plugin_id])) {
       $type = $base_plugin_id;
@@ -145,14 +145,6 @@ public function getDefinition($base_plugin_id, $exception_on_invalid = TRUE, $is
       'definition_class' => '\Drupal\Core\TypedData\DataDefinition',
       'type' => $type,
     );
-    // If this is definition expected for a config name and it is defined as a
-    // mapping, add a langcode element if not already present.
-    if ($is_config_name && isset($definition['mapping']) && !isset($definition['mapping']['langcode'])) {
-      $definition['mapping']['langcode'] = array(
-        'type' => 'string',
-        'label' => 'Language code',
-      );
-    }
     return $definition;
   }
 
diff --git a/core/lib/Drupal/Core/Config/TypedConfigManagerInterface.php b/core/lib/Drupal/Core/Config/TypedConfigManagerInterface.php
index e9e562e..0b793bd 100644
--- a/core/lib/Drupal/Core/Config/TypedConfigManagerInterface.php
+++ b/core/lib/Drupal/Core/Config/TypedConfigManagerInterface.php
@@ -110,16 +110,12 @@ public function hasConfigSchema($name);
    * @param bool $exception_on_invalid
    *   Ignored with TypedConfigManagerInterface. Kept for compatibility with
    *   DiscoveryInterface.
-   * @param bool $is_config_name
-   *   (deprecated) Set to TRUE if $plugin_id is a configuration name (as
-   *   opposed to an internal configuration schema type).
    *
    * @return array
    *   A plugin definition array. If the given plugin id does not have typed
    *   configuration definition assigned, the definition of an undefined
-   *   element type is returned. If $is_config_name is set, a langcode key
-   *   is automatically added to the definition.
+   *   element type is returned.
    */
-  public function getDefinition($plugin_id, $exception_on_invalid = TRUE, $is_config_name = FALSE);
+  public function getDefinition($plugin_id, $exception_on_invalid = TRUE);
 
 }