diff --git a/core/modules/simpletest/src/TestDiscovery.php b/core/modules/simpletest/src/TestDiscovery.php
index d5d7d8a576..f6ac67cd53 100644
--- a/core/modules/simpletest/src/TestDiscovery.php
+++ b/core/modules/simpletest/src/TestDiscovery.php
@@ -189,14 +189,17 @@ public function getTestClasses($extension = NULL, array $types = []) {
         // abstract class, trait or test fixture.
         continue;
       }
-      // Skip this test class if it requires unavailable modules.
-      // @todo PHPUnit skips tests with unmet requirements when executing a test
-      //   (instead of excluding them upfront). Refactor test runner to follow
-      //   that approach.
+      // Skip this test class if it is a Simpletest-based test and requires
+      // unavailable modules. TestDiscovery should not filter out module
+      // requirements for PHPUnit-based test classes.
+      // @todo Move this behavior to \Drupal\simpletest\TestBase so tests can be
+      //       marked as skipped, instead.
       // @see https://www.drupal.org/node/1273478
-      if (!empty($info['requires']['module'])) {
-        if (array_diff($info['requires']['module'], $this->availableExtensions['module'])) {
-          continue;
+      if ($info['type'] == 'Simpletest') {
+        if (!empty($info['requires']['module'])) {
+          if (array_diff($info['requires']['module'], $this->availableExtensions['module'])) {
+            continue;
+          }
         }
       }
 
diff --git a/core/modules/simpletest/src/Tests/SkipRequiredModulesTest.php b/core/modules/simpletest/src/Tests/SkipRequiredModulesTest.php
new file mode 100644
index 0000000000..15469433df
--- /dev/null
+++ b/core/modules/simpletest/src/Tests/SkipRequiredModulesTest.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace Drupal\simpletest\Tests;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests if Simpletest-based tests are skipped based on module requirements.
+ *
+ * This test should always be skipped when TestDiscovery is used to discover it.
+ * This means that if you specify this test to run-tests.sh with --class or
+ * --file, this test will run and fail.
+ *
+ * @dependencies simpletest_module_dne
+ *
+ * @group simpletest
+ *
+ * @todo Change or remove this test when Simpletest-based tests are able to skip
+ *       themselves based on requirements.
+ * @see https://www.drupal.org/node/1273478
+ */
+class SkipRequiredModulesTest extends WebTestBase {
+
+  public function testModuleNotFound() {
+    $this->fail('This test should have been skipped during discovery.');
+  }
+
+}
diff --git a/core/modules/simpletest/tests/src/Functional/MissingDependentModuleUnitTest.php b/core/modules/simpletest/tests/src/Functional/MissingDependentModuleUnitTest.php
deleted file mode 100644
index acd55dd014..0000000000
--- a/core/modules/simpletest/tests/src/Functional/MissingDependentModuleUnitTest.php
+++ /dev/null
@@ -1,22 +0,0 @@
-<?php
-
-namespace Drupal\Tests\simpletest\Functional;
-
-use Drupal\Tests\BrowserTestBase;
-
-/**
- * This test should not load since it requires a module that is not found.
- *
- * @group simpletest
- * @dependencies simpletest_missing_module
- */
-class MissingDependentModuleUnitTest extends BrowserTestBase {
-
-  /**
-   * Ensure that this test will not be loaded despite its dependency.
-   */
-  public function testFail() {
-    $this->fail('Running test with missing required module.');
-  }
-
-}
diff --git a/core/modules/simpletest/tests/src/Unit/TestInfoParsingTest.php b/core/modules/simpletest/tests/src/Unit/TestInfoParsingTest.php
index df98377d15..abdeabe7ff 100644
--- a/core/modules/simpletest/tests/src/Unit/TestInfoParsingTest.php
+++ b/core/modules/simpletest/tests/src/Unit/TestInfoParsingTest.php
@@ -62,7 +62,7 @@ public function infoParserProvider() {
       [
         'name' => 'Drupal\FunctionalTests\BrowserTestBaseTest',
         'group' => 'browsertestbase',
-        'description' => 'Tests BrowserTestBase functionality.',
+        'description' => 'Tests \Drupal\Tests\BrowserTestBase.',
         'type' => 'PHPUnit-Functional',
       ],
       // Classname.
diff --git a/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php b/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
index f73084f6f4..cd2b922e9e 100644
--- a/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
+++ b/core/tests/Drupal/FunctionalTests/BrowserTestBaseTest.php
@@ -11,6 +11,7 @@
 /**
  * Tests BrowserTestBase functionality.
  *
+ * @coversDefaultClass \Drupal\Tests\BrowserTestBase
  * @group browsertestbase
  */
 class BrowserTestBaseTest extends BrowserTestBase {
@@ -232,4 +233,48 @@ public function testInstall() {
     $this->assertTrue(file_exists($htaccess_filename), "$htaccess_filename exists");
   }
 
+  /**
+   * Tests that a test method is skipped when it requires a module not present.
+   *
+   * In order to catch checkRequirements() regressions, we have to make a new
+   * test object and run checkRequirements() here.
+   *
+   * @covers ::checkRequirements
+   * @covers ::checkModuleRequirements
+   */
+  public function testMethodRequiresModule() {
+    require __DIR__ . '/../../fixtures/BrowserMissingDependentModuleMethodTest.php';
+
+    $test = new BrowserMissingDependentModuleMethodTest();
+    // We have to setName() to the method name we're concerned with.
+    $test->setName('testRequiresModule');
+    $this->setExpectedException(
+      \PHPUnit_Framework_SkippedTestError::class,
+      'Module drupal_dne_module is required.'
+    );
+    $test->checkRequirements();
+  }
+
+  /**
+   * Tests that a test case is skipped when it requires a module not present.
+   *
+   * In order to catch checkRequirements() regressions, we have to make a new
+   * test object and run checkRequirements() here.
+   *
+   * @covers ::checkRequirements
+   * @covers ::checkModuleRequirements
+   */
+  public function testRequiresModule() {
+    require __DIR__ . '/../../fixtures/BrowserMissingDependentModuleTest.php';
+
+    $test = new BrowserMissingDependentModuleTest();
+    // We have to setName() to the method name we're concerned with.
+    $test->setName('testRequiresModule');
+    $this->setExpectedException(
+      \PHPUnit_Framework_SkippedTestError::class,
+      'Module drupal_dne_module is required.'
+    );
+    $test->checkRequirements();
+  }
+
 }
diff --git a/core/tests/Drupal/KernelTests/KernelTestBase.php b/core/tests/Drupal/KernelTests/KernelTestBase.php
index 5621d4aa19..22e35575f0 100644
--- a/core/tests/Drupal/KernelTests/KernelTestBase.php
+++ b/core/tests/Drupal/KernelTests/KernelTestBase.php
@@ -21,6 +21,7 @@
 use Drupal\simpletest\AssertHelperTrait;
 use Drupal\Tests\ConfigTestTrait;
 use Drupal\Tests\RandomGeneratorTrait;
+use Drupal\Tests\TestRequirementsTrait;
 use Drupal\simpletest\TestServiceProvider;
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\HttpFoundation\Request;
@@ -45,9 +46,6 @@
  *
  * @see \Drupal\Tests\KernelTestBase::$modules
  * @see \Drupal\Tests\KernelTestBase::enableModules()
- *
- * @todo Extend ::setRequirementsFromAnnotation() and ::checkRequirements() to
- *   account for '@requires module'.
  */
 abstract class KernelTestBase extends \PHPUnit_Framework_TestCase implements ServiceProviderInterface {
 
@@ -56,6 +54,7 @@
   use AssertHelperTrait;
   use RandomGeneratorTrait;
   use ConfigTestTrait;
+  use TestRequirementsTrait;
 
   /**
    * {@inheritdoc}
@@ -215,15 +214,6 @@ public static function setUpBeforeClass() {
   }
 
   /**
-   * Returns the drupal root directory.
-   *
-   * @return string
-   */
-  protected static function getDrupalRoot() {
-    return dirname(dirname(substr(__DIR__, 0, -strlen(__NAMESPACE__))));
-  }
-
-  /**
    * {@inheritdoc}
    */
   protected function setUp() {
diff --git a/core/tests/Drupal/KernelTests/KernelTestBaseTest.php b/core/tests/Drupal/KernelTests/KernelTestBaseTest.php
index 7d89fd7bd8..6c7fe8adab 100644
--- a/core/tests/Drupal/KernelTests/KernelTestBaseTest.php
+++ b/core/tests/Drupal/KernelTests/KernelTestBaseTest.php
@@ -206,6 +206,50 @@ public function testRenderWithTheme() {
   }
 
   /**
+   * Tests that a test method is skipped when it requires a module not present.
+   *
+   * In order to catch checkRequirements() regressions, we have to make a new
+   * test object and run checkRequirements() here.
+   *
+   * @covers ::checkRequirements
+   * @covers ::checkModuleRequirements
+   */
+  public function testMethodRequiresModule() {
+    require __DIR__ . '/../../fixtures/KernelMissingDependentModuleMethodTest.php';
+
+    $test = new KernelMissingDependentModuleMethodTest();
+    // We have to setName() to the method name we're concerned with.
+    $test->setName('testRequiresModule');
+    $this->setExpectedException(
+      \PHPUnit_Framework_SkippedTestError::class,
+      'Module drupal_dne_module is required.'
+    );
+    $test->checkRequirements();
+  }
+
+  /**
+   * Tests that a test case is skipped when it requires a module not present.
+   *
+   * In order to catch checkRequirements() regressions, we have to make a new
+   * test object and run checkRequirements() here.
+   *
+   * @covers ::checkRequirements
+   * @covers ::checkModuleRequirements
+   */
+  public function testRequiresModule() {
+    require __DIR__ . '/../../fixtures/KernelMissingDependentModuleTest.php';
+
+    $test = new KernelMissingDependentModuleTest();
+    // We have to setName() to the method name we're concerned with.
+    $test->setName('testRequiresModule');
+    $this->setExpectedException(
+      \PHPUnit_Framework_SkippedTestError::class,
+      'Module drupal_dne_module is required.'
+    );
+    $test->checkRequirements();
+  }
+
+  /**
    * {@inheritdoc}
    */
   protected function tearDown() {
diff --git a/core/tests/Drupal/Tests/BrowserTestBase.php b/core/tests/Drupal/Tests/BrowserTestBase.php
index 754f9d9838..e6498d9d0e 100644
--- a/core/tests/Drupal/Tests/BrowserTestBase.php
+++ b/core/tests/Drupal/Tests/BrowserTestBase.php
@@ -60,6 +60,7 @@
     createContentType as drupalCreateContentType;
   }
   use ConfigTestTrait;
+  use TestRequirementsTrait;
   use UserCreationTrait {
     createRole as drupalCreateRole;
     createUser as drupalCreateUser;
diff --git a/core/tests/Drupal/Tests/TestRequirementsTrait.php b/core/tests/Drupal/Tests/TestRequirementsTrait.php
new file mode 100644
index 0000000000..43a529e5c6
--- /dev/null
+++ b/core/tests/Drupal/Tests/TestRequirementsTrait.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace Drupal\Tests;
+
+use Drupal\Core\Extension\ExtensionDiscovery;
+
+/**
+ * Allows test classes to require Drupal modules as dependencies.
+ *
+ * This trait is assumed to be on a subclass of \PHPUnit_Framework_TestCase, and
+ * overrides \PHPUnit_Framework_TestCase::checkRequirements(). This
+ * allows the test to be marked as skipped before any kernel boot processes have
+ * happened.
+ */
+trait TestRequirementsTrait {
+
+  /**
+   * Returns the Drupal root directory.
+   *
+   * @return string
+   */
+  protected static function getDrupalRoot() {
+    return dirname(dirname(substr(__DIR__, 0, -strlen(__NAMESPACE__))));
+  }
+
+  /**
+   * Check module requirements for the Drupal use-case.
+   *
+   * This method is assumed to override
+   * \PHPUnit_Framework_TestCase::checkRequirements().
+   *
+   * @throws \PHPUnit_Framework_SkippedTestError
+   *   Thrown when the requirements are not met, and this test should be
+   *   skipped. Callers should not catch this exception.
+   */
+  protected function checkRequirements() {
+    parent::checkRequirements();
+
+    $root = static::getDrupalRoot();
+
+    // Check if required dependencies exist.
+    $annotations = $this->getAnnotations();
+    if (!empty($annotations['class']['requires'])) {
+      $this->checkModuleRequirements($root, $annotations['class']['requires']);
+    }
+    if (!empty($annotations['method']['requires'])) {
+      $this->checkModuleRequirements($root, $annotations['method']['requires']);
+    }
+  }
+
+  /**
+   * Checks missing module requirements.
+   *
+   * Iterates through a list of requires annotations and looks for missing
+   * modules. The test will be skipped if any of the required modules is
+   * missing.
+   *
+   * @param string $root
+   *   The path to the root of the Drupal installation to scan.
+   * @param string[] $annotations
+   *   A list of requires annotations from either a method or class annotation.
+   *
+   * @throws \PHPUnit_Framework_SkippedTestError
+   *   Thrown when the requirements are not met, and this test should be
+   *   skipped. Callers should not catch this exception.
+   */
+  private function checkModuleRequirements($root, array $annotations) {
+    // drupal_valid_ua() might not be loaded.
+    require_once $root . '/core/includes/bootstrap.inc';
+    // Scan for modules.
+    $discovery = new ExtensionDiscovery($root, FALSE);
+    $discovery->setProfileDirectories([]);
+    $list = $discovery->scan('module');
+    // Find requirements in the list of modules.
+    foreach ($annotations as $requirement) {
+      if (strpos($requirement, 'module ') === 0) {
+        $module = trim(str_replace('module ', '', $requirement));
+        if (!isset($list[$module])) {
+          throw new \PHPUnit_Framework_SkippedTestError("Module $module is required.");
+        }
+      }
+    }
+  }
+
+}
diff --git a/core/tests/fixtures/BrowserMissingDependentModuleMethodTest.php b/core/tests/fixtures/BrowserMissingDependentModuleMethodTest.php
new file mode 100644
index 0000000000..5ce348baf3
--- /dev/null
+++ b/core/tests/fixtures/BrowserMissingDependentModuleMethodTest.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace Drupal\FunctionalTests;
+
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * A fixture test class with requires annotation.
+ *
+ * This is a fixture class for
+ * \Drupal\KernelTests\KernelTestBaseTest::testRequiresModule().
+ *
+ * This test class should not be discovered by run-tests.sh or phpunit.
+ *
+ * @group fixture
+ */
+class BrowserMissingDependentModuleMethodTest extends BrowserTestBase {
+
+  /**
+   * This method should be skipped since it requires a module that is not found.
+   *
+   * @requires module drupal_dne_module
+   */
+  public function testRequiresModule() {
+    $this->fail('Running test with missing required module.');
+  }
+
+}
diff --git a/core/tests/fixtures/BrowserMissingDependentModuleTest.php b/core/tests/fixtures/BrowserMissingDependentModuleTest.php
new file mode 100644
index 0000000000..443a93deda
--- /dev/null
+++ b/core/tests/fixtures/BrowserMissingDependentModuleTest.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace Drupal\FunctionalTests;
+
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * A fixture test class with requires annotation.
+ *
+ * This is a fixture class for
+ * \Drupal\KernelTests\KernelTestBaseTest::testRequiresModule().
+ *
+ * This test class should not be discovered by run-tests.sh or phpunit.
+ *
+ * @requires module drupal_dne_module
+ * @group fixture
+ */
+class BrowserMissingDependentModuleTest extends BrowserTestBase {
+
+  /**
+   * Placeholder test method.
+   *
+   * Depending on configuration, PHPUnit might fail a test if it has no test
+   * methods, so we must provide one. This method should never be executed.
+   */
+  public function testRequiresModule() {
+    $this->fail('Running test with missing required module.');
+  }
+
+}
diff --git a/core/tests/fixtures/KernelMissingDependentModuleMethodTest.php b/core/tests/fixtures/KernelMissingDependentModuleMethodTest.php
new file mode 100644
index 0000000000..ab2b4d8956
--- /dev/null
+++ b/core/tests/fixtures/KernelMissingDependentModuleMethodTest.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Drupal\KernelTests;
+
+/**
+ * A fixture test class with requires annotation.
+ *
+ * This is a fixture class for
+ * \Drupal\KernelTests\KernelTestBaseTest::testRequiresModule().
+ *
+ * This test class should not be discovered by run-tests.sh or phpunit.
+ *
+ * @group fixture
+ */
+class KernelMissingDependentModuleMethodTest extends KernelTestBase {
+
+  /**
+   * This method should be skipped since it requires a module that is not found.
+   *
+   * @requires module drupal_dne_module
+   */
+  public function testRequiresModule() {
+    $this->fail('Running test with missing required module.');
+  }
+
+}
diff --git a/core/tests/fixtures/KernelMissingDependentModuleTest.php b/core/tests/fixtures/KernelMissingDependentModuleTest.php
new file mode 100644
index 0000000000..2ba5a5aad8
--- /dev/null
+++ b/core/tests/fixtures/KernelMissingDependentModuleTest.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace Drupal\KernelTests;
+
+/**
+ * A fixture test class with requires annotation.
+ *
+ * This is a fixture class for
+ * \Drupal\KernelTests\KernelTestBaseTest::testRequiresModule().
+ *
+ * This test class should not be discovered by run-tests.sh or phpunit.
+ *
+ * @requires module drupal_dne_module
+ * @group fixture
+ */
+class KernelMissingDependentModuleTest extends KernelTestBase {
+
+  /**
+   * Placeholder test method.
+   *
+   * Depending on configuration, PHPUnit might fail a test if it has no test
+   * methods, so we must provide one. This method should never be executed.
+   */
+  public function testRequiresModule() {
+    $this->fail('Running test with missing required module.');
+  }
+
+}