diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
index c274fff..62341ee 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
@@ -59,18 +59,8 @@ function testSchemaMapping() {
     $expected = array();
     $expected['label'] = 'Schema test data';
     $expected['class'] = '\Drupal\Core\Config\Schema\Mapping';
-    $expected['mapping']['testitem'] = array(
-      'label' => 'Test item',
-      'type' => 'string',
-    );
-    $expected['mapping']['testlist'] = array(
-      'label' => 'Test list',
-      'type' => 'sequence'
-    );
-    $expected['mapping']['testlist']['sequence'][] = array(
-      'type' => 'string',
-      'label' => 'Test',
-    );
+    $expected['mapping']['testitem'] = array('label' => 'Test item');
+    $expected['mapping']['testlist'] = array('label' => 'Test list');
     $this->assertEqual($definition, $expected, 'Retrieved the right metadata for configuration with only some schema.');
 
     // Check type detection on elements with undefined types.
@@ -84,12 +74,8 @@ function testSchemaMapping() {
     $definition = $config['testlist']->getDefinition();
     $expected = array();
     $expected['label'] = 'Test list';
-    $expected['class'] = '\Drupal\Core\Config\Schema\Sequence';
-    $expected['type'] = 'sequence';
-    $expected['sequence'][] = array(
-      'type' => 'string',
-      'label' => 'Test',
-    );
+    $expected['class'] = '\Drupal\Core\Config\Schema\Property';
+    $expected['type'] = 'undefined';
     $this->assertEqual($definition, $expected, 'Automatic type fallback on non-string item worked.');
 
     // Simple case, straight metadata.
diff --git a/core/modules/config/lib/Drupal/config/Tests/DefaultConfigTest.php b/core/modules/config/lib/Drupal/config/Tests/DefaultConfigTest.php
index 437c04e..c505bab 100644
--- a/core/modules/config/lib/Drupal/config/Tests/DefaultConfigTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/DefaultConfigTest.php
@@ -62,9 +62,11 @@ public function testDefaultConfig() {
       if (strpos($config_name, 'migrate.migration') === 0 || strpos($config_name, 'language.config') === 0) {
         continue;
       }
-      // config_test.noschema has to be skipped as it tests
+      // 1. config_test.noschema has to be skipped as it tests
       // TypedConfigManagerInterface::hasConfigSchema() method.
-      if ($config_name == 'config_test.noschema') {
+      // 2. config.someschema has to be skipped as it tests
+      // schema default data type fallback.
+      if ($config_name == 'config_test.noschema' || $config_name == 'config_test.someschema') {
         continue;
       }
 
diff --git a/core/modules/config/tests/config_test/config/schema/config_test.schema.yml b/core/modules/config/tests/config_test/config/schema/config_test.schema.yml
index 98f3050..a5c89e1 100644
--- a/core/modules/config/tests/config_test/config/schema/config_test.schema.yml
+++ b/core/modules/config/tests/config_test/config/schema/config_test.schema.yml
@@ -5,14 +5,9 @@ config_test.someschema:
   label: 'Schema test data'
   mapping:
     testitem:
-      type: string
       label: 'Test item'
     testlist:
-      type: sequence
       label: 'Test list'
-      sequence:
-        - type: string
-          label: 'Test'
 
 config_test.someschema.with_parents:
   label: 'Schema test data with parenting'