diff --git a/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
index f9c8470..b43c6a7 100644
--- a/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
+++ b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
@@ -83,7 +83,7 @@ protected function checkValue($key, $value) {
     }
     catch (SchemaIncompleteException $e) {
       if (is_scalar($value) || $value === NULL) {
-        return array($error_key => 'Missing schema.');
+        return array($error_key => 'Missing schema');
       }
     }
     // Do not check value if it is defined to be ignored.
diff --git a/core/modules/config/src/Tests/SchemaCheckTraitTest.php b/core/modules/config/src/Tests/SchemaCheckTraitTest.php
new file mode 100644
index 0000000..3b5793a
--- /dev/null
+++ b/core/modules/config/src/Tests/SchemaCheckTraitTest.php
@@ -0,0 +1,77 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\config\Tests\SchemaCheckTraitTest.
+ */
+
+namespace Drupal\config\Tests;
+
+use Drupal\Core\Config\Schema\SchemaCheckTrait;
+use Drupal\simpletest\KernelTestBase;
+
+
+/**
+ * Tests \Drupal\Core\Config\Schema\SchemaCheckTrait.
+ */
+class SchemaCheckTraitTest extends KernelTestBase {
+  use SchemaCheckTrait;
+
+  /**
+   * The typed config manager.
+   *
+   * @var \Drupal\Core\Config\TypedConfigManagerInterface
+   */
+  protected $typedConfig;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('config_test', 'config_schema_test');
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getInfo() {
+    return array(
+      'name' => 'SchemaCheckTrait test',
+      'description' => 'Tests the functionality of SchemaCheckTrait.',
+      'group' => 'Configuration',
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+    $this->installConfig(array('config_test', 'config_schema_test'));
+    $this->typedConfig = \Drupal::service('config.typed');
+  }
+
+  /**
+   * Tests \Drupal\Core\Config\Schema\SchemaCheckTrait.
+   */
+  public function testTrait() {
+    // Test a non existing schema.
+    $ret = $this->checkConfigSchema($this->typedConfig, 'config_schema_test.noschema', \Drupal::config('config_schema_test.noschema')->get());
+    $this->assertIdentical($ret, FALSE);
+
+    // Test an existing schema with valid data.
+    $config_data = \Drupal::config('config_test.types')->get();
+    $ret = $this->checkConfigSchema($this->typedConfig, 'config_test.types', $config_data);
+    $this->assertIdentical($ret, TRUE);
+
+    // Add a new key and new array to test the error messages.
+    $config_data = array('new_key' => 'new_value', 'new_array' => array()) + $config_data;
+    $ret = $this->checkConfigSchema($this->typedConfig, 'config_test.types', $config_data);
+    $expected = array(
+      'config_test.types:new_key' => 'Missing schema',
+      'config_test.types:new_array' => 'Non-scalar value but not defined as an array (such as mapping or sequence)',
+    );
+    $this->assertIdentical($ret, $expected);
+  }
+
+}