diff --git a/core/lib/Drupal/Core/Config/TypedConfigManager.php b/core/lib/Drupal/Core/Config/TypedConfigManager.php
index e82b1ccd90..bd5fa99812 100644
--- a/core/lib/Drupal/Core/Config/TypedConfigManager.php
+++ b/core/lib/Drupal/Core/Config/TypedConfigManager.php
@@ -49,15 +49,15 @@ class TypedConfigManager extends TypedDataManager implements TypedConfigManagerI
    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   The module handler.
    * @param \Drupal\Core\DependencyInjection\ClassResolverInterface $class_resolver
-   *   The class resolver.
+   *   (optional) The class resolver.
    */
-  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage, CacheBackendInterface $cache, ModuleHandlerInterface $module_handler, ClassResolverInterface $class_resolver) {
+  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage, CacheBackendInterface $cache, ModuleHandlerInterface $module_handler, ClassResolverInterface $class_resolver = NULL) {
     $this->configStorage = $configStorage;
     $this->schemaStorage = $schemaStorage;
     $this->setCacheBackend($cache, 'typed_config_definitions');
     $this->alterInfo('config_schema_info');
     $this->moduleHandler = $module_handler;
-    $this->classResolver = $class_resolver;
+    $this->classResolver = $class_resolver ?: \Drupal::service('class_resolver');
   }
 
   /**
diff --git a/core/lib/Drupal/Core/TypedData/TypedDataManager.php b/core/lib/Drupal/Core/TypedData/TypedDataManager.php
index 7f353be6e0..dbf0d5fec5 100644
--- a/core/lib/Drupal/Core/TypedData/TypedDataManager.php
+++ b/core/lib/Drupal/Core/TypedData/TypedDataManager.php
@@ -118,7 +118,10 @@ public function createDataDefinition($data_type) {
     }
     $class = $type_definition['definition_class'];
     $data_definition = $class::createFromDataType($data_type);
-    $data_definition->setTypedDataManager($this);
+
+    if (method_exists($data_definition, 'setTypedDataManager')) {
+      $data_definition->setTypedDataManager($this);
+    }
 
     return $data_definition;
   }
diff --git a/core/modules/config/tests/config_test/src/ConfigValidation.php b/core/modules/config/tests/config_test/src/ConfigValidation.php
index 7bf5f70522..c8e04d88cc 100644
--- a/core/modules/config/tests/config_test/src/ConfigValidation.php
+++ b/core/modules/config/tests/config_test/src/ConfigValidation.php
@@ -18,7 +18,7 @@ class ConfigValidation {
    *   The validation execution context.
    */
   public static function validateLlama($object, ExecutionContextInterface $context) {
-    if ($object !== 'meh') {
+    if (in_array($object, ['llama', 'alpaca', 'guanaco', 'vicuña'], TRUE)) {
       $context->addViolation('no valid llama');
     }
   }
diff --git a/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php b/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php
index ced7759647..d7b9ea2139 100644
--- a/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php
+++ b/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php
@@ -53,9 +53,10 @@ public function testTypedDataAPI() {
     $this->assertEquals('kitten', $mapping->get('type')->getValue());
     $this->assertInstanceOf(IntegerInterface::class, $mapping->get('count'));
     $this->assertEquals(2, $mapping->get('count')->getValue());
+    // Verify the item metadata is available.
     $this->assertInstanceOf(ComplexDataDefinitionInterface::class, $mapping->getDataDefinition());
-    // @todo: Make metadata about contained properties available and add test
-    // coverage here.
+    $this->assertArrayHasKey('type', $mapping->getProperties());
+    $this->assertArrayHasKey('count', $mapping->getProperties());
 
     // Test accessing sequences.
     $sequence = $typed_config->get('giraffe');