diff --git a/core/lib/Drupal/Component/Annotation/PluginID.php b/core/lib/Drupal/Component/Annotation/PluginID.php
index fe8e599..ab5e193 100644
--- a/core/lib/Drupal/Component/Annotation/PluginID.php
+++ b/core/lib/Drupal/Component/Annotation/PluginID.php
@@ -24,7 +24,7 @@ class PluginID extends AnnotationBase {
   public $value;
 
   /**
-   * Implements \Drupal\Core\Annotation\AnnotationInterface::get().
+   * {@inheritdoc}
    */
   public function get() {
     return array(
diff --git a/core/lib/Drupal/Component/Plugin/Exception/InvalidDecoratedMethod.php b/core/lib/Drupal/Component/Plugin/Exception/InvalidDecoratedMethod.php
index a810063..ffb76f0 100644
--- a/core/lib/Drupal/Component/Plugin/Exception/InvalidDecoratedMethod.php
+++ b/core/lib/Drupal/Component/Plugin/Exception/InvalidDecoratedMethod.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * @file
- * Definition of Drupal\Core\Plugin\Exception\InvalidDecoratedMethod.
+ * Definition of Drupal\Component\Plugin\Exception\InvalidDecoratedMethod.
  */
 
 namespace Drupal\Component\Plugin\Exception;
diff --git a/core/lib/Drupal/Component/Utility/SortArray.php b/core/lib/Drupal/Component/Utility/SortArray.php
index 79688ec..464867c 100644
--- a/core/lib/Drupal/Component/Utility/SortArray.php
+++ b/core/lib/Drupal/Component/Utility/SortArray.php
@@ -39,8 +39,6 @@ public static function sortByWeightElement(array $a, array $b) {
   /**
    * Sorts a structured array by '#weight' property.
    *
-   * Callback for uasort() within \Drupal\Core\Render\Element::children().
-   *
    * @param array $a
    *   First item for comparison. The compared items should be associative
    *   arrays that optionally include a '#weight' key.
diff --git a/core/lib/Drupal/Component/Utility/UrlHelper.php b/core/lib/Drupal/Component/Utility/UrlHelper.php
index 45a8036..691413e 100644
--- a/core/lib/Drupal/Component/Utility/UrlHelper.php
+++ b/core/lib/Drupal/Component/Utility/UrlHelper.php
@@ -288,9 +288,8 @@ public static function setAllowedProtocols(array $protocols = array()) {
    * to being output to an HTML attribute value. It is often called as part of
    * check_url() or Drupal\Component\Utility\Xss::filter(), but those functions
    * return an HTML-encoded string, so this function can be called independently
-   * when the output needs to be a plain-text string for passing to t(), _l(),
-   * Drupal\Core\Template\Attribute, or another function that will call
-   * \Drupal\Component\Utility\String::checkPlain() separately.
+   * when the output needs to be a plain-text string for passing to functions
+   * that will call \Drupal\Component\Utility\String::checkPlain() separately.
    *
    * @param string $uri
    *   A plain-text URI that might contain dangerous protocols.
diff --git a/core/tests/Drupal/Tests/Component/DrupalComponentTest.php b/core/tests/Drupal/Tests/Component/DrupalComponentTest.php
new file mode 100644
index 0000000..2f078df
--- /dev/null
+++ b/core/tests/Drupal/Tests/Component/DrupalComponentTest.php
@@ -0,0 +1,69 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\Component\DrupalComponentTest.
+ */
+
+namespace Drupal\Tests\Component;
+
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * General tests for Drupal\Component that can't go anywhere else.
+ *
+ * @group Drupal
+ * @group Component
+ */
+class DrupalComponentTest extends UnitTestCase {
+
+  /**
+   * Tests that classes in Component do not use any Core class.
+   */
+  public function testNoCoreInComponent() {
+    $component_path = dirname(substr(__DIR__, 0, -strlen(__NAMESPACE__))) . '/lib/Drupal/Component';
+    foreach ($this->findPhpClasses($component_path) as $class) {
+      $this->assertNoCoreUsage($class);
+    }
+  }
+
+  /**
+   * Searches a directory recursively for php classes.
+   *
+   * @param string $dir
+   *   The full path to the directory that should be checked.
+   *
+   * @return array
+   *   An array of class paths.
+   */
+  protected function findPhpClasses($dir) {
+    $classes = array();
+    foreach (new \DirectoryIterator($dir) as $file) {
+      if ($file->isDir() && !$file->isDot()) {
+        $classes = array_merge($classes, $this->findPhpClasses($file->getPathname()));
+      }
+      elseif ($file->getExtension() == 'php') {
+        $classes[] = $file->getPathname();
+      }
+    }
+
+    return $classes;
+  }
+
+  /**
+   * Asserts that the file is not using any class from Drupal\Core.
+   *
+   * @param string $class_path
+   *   The full path to the class that should be checked.
+   */
+  protected function assertNoCoreUsage($class_path) {
+    foreach (new \SplFileObject($class_path) as $line) {
+      // Allow linking to Core files with @see docs. Its harmless and boosts DX
+      // because even outside projects can treat those links as examples.
+      if ($line && !strpos($line, '@see ')) {
+        $this->assertFalse(strpos($line, 'Drupal\\Core'));
+      }
+    }
+  }
+
+}