diff --git a/core/lib/Drupal/Core/Extension/module.api.php b/core/lib/Drupal/Core/Extension/module.api.php
index 7acc0fd..e1e0e58 100644
--- a/core/lib/Drupal/Core/Extension/module.api.php
+++ b/core/lib/Drupal/Core/Extension/module.api.php
@@ -748,7 +748,8 @@ function hook_updater_info_alter(&$updaters) {
  *   - value: The current value (e.g., version, time, level, etc). During
  *     install phase, this should only be used for version numbers, do not set
  *     it if not applicable.
- *   - description: The description of the requirement/status.
+ *   - description: The description of the requirement/status. May be either a
+ *     string or a render array.
  *   - severity: The requirement's result/severity level, one of:
  *     - REQUIREMENT_INFO: For info only.
  *     - REQUIREMENT_OK: The requirement is satisfied.
diff --git a/core/modules/system/src/Tests/Module/HookRequirementsOutputTest.php b/core/modules/system/src/Tests/Module/HookRequirementsOutputTest.php
new file mode 100644
index 0000000..72ccaea
--- /dev/null
+++ b/core/modules/system/src/Tests/Module/HookRequirementsOutputTest.php
@@ -0,0 +1,50 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\system\Tests\Module\HookRequirementsTest.
+ */
+
+namespace Drupal\system\Tests\Module;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests the output of hook_requirements().
+ *
+ * @group Module
+ */
+class HookRequirementsOutputTest extends WebTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('requirements3_test');
+
+  protected function setUp() {
+    parent::setUp();
+
+    $admin_user = $this->drupalCreateUser(array('access administration pages', 'administer site configuration'));
+    $this->drupalLogin($admin_user);
+  }
+
+  /**
+   * Tests the hook output with both a string and render array.
+   *
+   * @todo We should possibly test both the install and runtime phases.
+   */
+  function testHookRequirementsOutput() {
+    \Drupal::state()->set('requirements3_test.description_array', FALSE);
+    $this->drupalGet('admin/reports/status');
+    $this->assertText(t('Requirements 3 Test'));
+    $this->assertText(t('Requirements 3 string.'));
+    \Drupal::state()->set('requirements3_test.description_array', TRUE);
+    $this->drupalGet('admin/reports/status');
+    $this->assertText(t('Requirements 3 Test'));
+    $this->assertText(t('Requirements list'));
+    $this->assertText(t('First message'));
+    $this->assertText(t('Second message'));
+  }
+}
diff --git a/core/modules/system/tests/modules/requirements3_test/requirements3_test.info.yml b/core/modules/system/tests/modules/requirements3_test/requirements3_test.info.yml
new file mode 100644
index 0000000..b5affe8
--- /dev/null
+++ b/core/modules/system/tests/modules/requirements3_test/requirements3_test.info.yml
@@ -0,0 +1,6 @@
+name: 'Requirements 3 Test'
+type: module
+description: 'Tests output of hook_requirements().'
+package: Testing
+version: VERSION
+core: 8.x
diff --git a/core/modules/system/tests/modules/requirements3_test/requirements3_test.install b/core/modules/system/tests/modules/requirements3_test/requirements3_test.install
new file mode 100644
index 0000000..f7b6d38
--- /dev/null
+++ b/core/modules/system/tests/modules/requirements3_test/requirements3_test.install
@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * @file
+ * Install, update and uninstall functions for the requirements3_test module.
+ */
+
+/**
+ * Implements hook_requirements().
+ */
+function requirements3_test_requirements($phase) {
+  $requirements = array();
+
+  // Always fails requirements.
+  if (\Drupal::state()->get('requirements3_test.description_array')) {
+    $requirements['requirements3_test'] = array(
+      'title' => t('Requirements 3 Test'),
+      'severity' => REQUIREMENT_WARNING,
+      'description' => [
+        '#theme' => 'item_list',
+        '#title' => t('Requirements list'),
+        '#items' => [t('First message'), t('Second message')],
+      ]
+    );
+  }
+  else{
+    $requirements['requirements3_test'] = array(
+      'title' => t('Requirements 3 Test'),
+      'severity' => REQUIREMENT_WARNING,
+      'description' => t('Requirements 3 string.'),
+    );
+  }
+
+  return $requirements;
+}