diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 7bff76e..5676d32 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1035,6 +1035,13 @@ function theme($hook, $variables = array()) {
   $variables += array(
     'theme_hook_original' => $original_hook,
   );
+  // If theme() is called with a suggestion like comment__node_article, include
+  // information about the base hook - e.g. 'comment'.
+  if ($hook != $original_hook) {
+    $variables += array(
+      'theme_hook_base' => $hook,
+    );
+  }
 
   // Invoke the variable processors, if any. The processors may specify
   // alternate suggestions for which hook's template/function to use. If the
diff --git a/core/modules/system/lib/Drupal/system/Tests/Theme/TwigDebugMarkupTest.php b/core/modules/system/lib/Drupal/system/Tests/Theme/TwigDebugMarkupTest.php
index 38e183b..c13fdcf 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Theme/TwigDebugMarkupTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Theme/TwigDebugMarkupTest.php
@@ -19,7 +19,7 @@ class TwigDebugMarkupTest extends WebTestBase {
    *
    * @var array
    */
-  public static $modules = array('theme_test');
+  public static $modules = array('theme_test', 'comment');
 
   public static function getInfo() {
     return array(
@@ -67,6 +67,25 @@ function testTwigDebugMarkup() {
     $this->assertTrue(strpos($output, '* node--2' . $extension) !== FALSE, 'Node ID specific template suggestion found.');
     $this->assertTrue(strpos($output, 'x node' . $extension) !== FALSE, 'Base template file shown as current template.');
 
+    // Create another node, call a theme suggestion directly, and make sure the
+    // template suggestions shown in the debug markup are correct.
+    $node3 = $this->drupalCreateNode();
+    $comment = entity_create('comment', array(
+      'cid' => NULL,
+      'nid' => $node3->id(),
+      'node_type' => $node3->type,
+      'pid' => 0,
+      'uid' => 0,
+      'status' => COMMENT_PUBLISHED,
+      'subject' => $this->randomName(),
+      'hostname' => '127.0.0.1',
+      'langcode' => 'und',
+      'comment_body' => array('und' => array($this->randomName())),
+    ));
+    $comment->save();
+    $output = theme('comment__node__article', comment_view($comment));
+    $this->assertTrue(strpos($output, 'x comment' . $extension) !== FALSE, 'Suggested template file shown as current template.');
+
     // Disable debug, rebuild the service container, and clear all caches.
     $this->settingsSet('twig_debug', FALSE);
     $this->rebuildContainer();
diff --git a/core/themes/engines/twig/twig.engine b/core/themes/engines/twig/twig.engine
index b541cdc..8174486 100644
--- a/core/themes/engines/twig/twig.engine
+++ b/core/themes/engines/twig/twig.engine
@@ -62,6 +62,9 @@ function twig_render_template($template_file, $variables) {
       $current_template = basename($template_file);
       $suggestions = $variables['theme_hook_suggestions'];
       $suggestions[] = $variables['theme_hook_original'];
+      if (isset($variables['theme_hook_base'])) {
+        $suggestions[] = $variables['theme_hook_base'];
+      }
       foreach ($suggestions as $key => &$suggestion) {
         $template = strtr($suggestion, '_', '-') . $extension;
         $prefix = ($template == $current_template) ? 'x' : '*';