diff --git a/core/modules/system/src/Tests/Theme/ThemeSuggestionsAlterTest.php b/core/modules/system/src/Tests/Theme/ThemeSuggestionsAlterTest.php
index 6957f27..15962c2 100644
--- a/core/modules/system/src/Tests/Theme/ThemeSuggestionsAlterTest.php
+++ b/core/modules/system/src/Tests/Theme/ThemeSuggestionsAlterTest.php
@@ -157,7 +157,7 @@ public function testSuggestionsAlterInclude() {
   }
 
   /**
-   * Tests hook_theme_suggestions_HOOK().
+   * Tests hook_theme_suggestions_HOOK() with direct array suggestions.
    */
   public function testArraySuggestions() {
     $this->drupalGet('theme-test/array-suggestions');
diff --git a/core/modules/system/src/Tests/Theme/TwigDebugMarkupTest.php b/core/modules/system/src/Tests/Theme/TwigDebugMarkupTest.php
index cd2e2fd..d25e5d4 100644
--- a/core/modules/system/src/Tests/Theme/TwigDebugMarkupTest.php
+++ b/core/modules/system/src/Tests/Theme/TwigDebugMarkupTest.php
@@ -43,7 +43,7 @@ protected function setUp() {
   /**
    * Tests debug markup added to Twig template output.
    */
-  function testTwigDebugMarkup() {
+  public function testTwigDebugMarkup() {
     $extension = twig_extension();
     $cache = $this->container->get('theme.registry')->get();
     // Create array of Twig templates.
@@ -96,10 +96,20 @@ function testTwigDebugMarkup() {
   public function testArraySuggestionsTwigDebugMarkup() {
     \Drupal::service('module_installer')->install(array('theme_suggestions_test'));
     $extension = twig_extension();
-
     $this->drupalGet('theme-test/array-suggestions');
-    $this->assertTrue(strpos($this->getRawContent(), "THEME HOOK: 'theme_test_array_suggestions'") !== FALSE, 'Theme call information found.');
-    $this->assertTrue(strpos($this->getRawContent(), '<!-- FILE NAME SUGGESTIONS:' . PHP_EOL .  '   * theme-test-array-suggestions--not-implemented' . $extension . PHP_EOL .  '   * theme-test-array-suggestions--not-implemented-2' . $extension . PHP_EOL . '   x theme-test-array-suggestions--suggestion-from-hook' . $extension . PHP_EOL . '   * theme-test-array-suggestions' . $extension . PHP_EOL . '-->') !== FALSE, 'Suggested template files found in order and correct suggestion shown as current template.');
+    $output = $this->getRawContent();
+
+    $expected = "THEME HOOK: 'theme_test_array_suggestions'";
+    $this->assertTrue(strpos($output, $expected) !== FALSE, 'Theme call information found.');
+
+    $expected = '<!-- FILE NAME SUGGESTIONS:' . PHP_EOL
+      . '   * theme-test-array-suggestions--not-implemented' . $extension . PHP_EOL
+      . '   * theme-test-array-suggestions--not-implemented-2' . $extension . PHP_EOL
+      . '   x theme-test-array-suggestions--suggestion-from-hook' . $extension . PHP_EOL
+      . '   * theme-test-array-suggestions' . $extension . PHP_EOL
+      . '-->';
+    $message = 'Suggested template files found in order and correct suggestion shown as current template.';
+    $this->assertTrue(strpos($output, $expected) !== FALSE, $message);
   }
 
   /**
@@ -108,8 +118,18 @@ public function testArraySuggestionsTwigDebugMarkup() {
   public function testUnimplementedSpecificSuggestionsTwigDebugMarkup() {
     $extension = twig_extension();
     $this->drupalGet('theme-test/specific-suggestion');
-    $this->assertTrue(strpos($this->getRawContent(), "THEME HOOK: 'theme_test_specific_suggestions__not__found'") !== FALSE, 'Theme call information found.');
-    $this->assertTrue(strpos($this->getRawContent(), '<!-- FILE NAME SUGGESTIONS:' . PHP_EOL . '   * theme-test-specific-suggestions--not--found' . $extension . PHP_EOL  . '   * theme-test-specific-suggestions--not' . $extension . PHP_EOL . '   x theme-test-specific-suggestions' . $extension . PHP_EOL . '-->') !== FALSE, 'Suggested template files found in order and base template shown as current template.');
+    $output = $this->getRawContent();
+
+    $expected = "THEME HOOK: 'theme_test_specific_suggestions__not__found'";
+    $this->assertTrue(strpos($output, $expected) !== FALSE, 'Theme call information found.');
+
+    $message = 'Suggested template files found in order and base template shown as current template.';
+    $expected = '<!-- FILE NAME SUGGESTIONS:' . PHP_EOL
+      . '   * theme-test-specific-suggestions--not--found' . $extension . PHP_EOL
+      . '   * theme-test-specific-suggestions--not' . $extension . PHP_EOL
+      . '   x theme-test-specific-suggestions' . $extension . PHP_EOL
+      . '-->';
+    $this->assertTrue(strpos($output, $expected) !== FALSE, $message);
   }
 
   /**
@@ -118,8 +138,17 @@ public function testUnimplementedSpecificSuggestionsTwigDebugMarkup() {
   public function testSpecificSuggestionsTwigDebugMarkup() {
     $extension = twig_extension();
     $this->drupalGet('theme-test/specific-suggestion-alter');
-    $this->assertTrue(strpos($this->getRawContent(), "THEME HOOK: 'theme_test_specific_suggestions__variant'") !== FALSE, 'Theme call information found.');
-    $this->assertTrue(strpos($this->getRawContent(), '<!-- FILE NAME SUGGESTIONS:' . PHP_EOL . '   x theme-test-specific-suggestions--variant' . $extension . PHP_EOL . '   * theme-test-specific-suggestions' . $extension . PHP_EOL . '-->') !== FALSE, 'Suggested template files found in order and suggested template shown as current.');
+    $output = $this->getRawContent();
+
+    $expected = "THEME HOOK: 'theme_test_specific_suggestions__variant'";
+    $this->assertTrue(strpos($output, $expected) !== FALSE, 'Theme call information found.');
+
+    $expected = '<!-- FILE NAME SUGGESTIONS:' . PHP_EOL
+      . '   x theme-test-specific-suggestions--variant' . $extension . PHP_EOL
+      . '   * theme-test-specific-suggestions' . $extension . PHP_EOL
+      . '-->';
+    $message = 'Suggested template files found in order and suggested template shown as current.';
+    $this->assertTrue(strpos($output, $expected) !== FALSE, $message);
   }
 
 }
diff --git a/core/modules/system/tests/modules/theme_test/src/ThemeTestController.php b/core/modules/system/tests/modules/theme_test/src/ThemeTestController.php
index 191102d..4b59b0e 100644
--- a/core/modules/system/tests/modules/theme_test/src/ThemeTestController.php
+++ b/core/modules/system/tests/modules/theme_test/src/ThemeTestController.php
@@ -147,7 +147,8 @@ public function arraySuggestions() {
       '#theme' => array(
         'theme_test_array_suggestions__not_implemented',
         'theme_test_array_suggestions__not_implemented_2',
-        'theme_test_array_suggestions'),
+        'theme_test_array_suggestions',
+      ),
     );
   }
 
diff --git a/core/modules/views/src/Tests/ViewsThemeIntegrationTest.php b/core/modules/views/src/Tests/ViewsThemeIntegrationTest.php
index 6c67ee8..41bc7ea 100644
--- a/core/modules/views/src/Tests/ViewsThemeIntegrationTest.php
+++ b/core/modules/views/src/Tests/ViewsThemeIntegrationTest.php
@@ -95,15 +95,15 @@ public function testThemeSuggestionsInDebug() {
       '#type' => 'view',
       '#name' => 'test_page_display',
       '#display_id' => 'default',
-      '#arguments' => array(),
+      '#arguments' => [],
     ];
 
     $output = drupal_render($build, TRUE);
-
-    $this->assertTrue(strpos($output, '* views-view--test-page-display--default.html.twig') !== FALSE);
-    $this->assertTrue(strpos($output, '* views-view--default.html.twig') !== FALSE);
-    $this->assertTrue(strpos($output, '* views-view--test-page-display.html.twig') !== FALSE);
-    $this->assertTrue(strpos($output, 'x views-view.html.twig') !== FALSE);
+    $expected = '   * views-view--test-page-display--default.html.twig' . PHP_EOL
+      . '   * views-view--default.html.twig' . PHP_EOL
+      . '   * views-view--test-page-display.html.twig' . PHP_EOL
+      . '   x views-view.html.twig' . PHP_EOL;
+    $this->assertTrue(strpos($output, $expected) !== FALSE);
   }
 
 }
diff --git a/core/themes/engines/twig/twig.engine b/core/themes/engines/twig/twig.engine
index 19c6a28..ff71af0 100644
--- a/core/themes/engines/twig/twig.engine
+++ b/core/themes/engines/twig/twig.engine
@@ -73,15 +73,13 @@ function twig_render_template($template_file, array $variables) {
       $current_template = basename($template_file);
       $pos = strpos($variables['theme_hook_original'], '__');
 
-      if ( $pos !== FALSE) {
+      if ($pos !== FALSE) {
         $suggestions[] = substr($variables['theme_hook_original'], 0, $pos);
       }
       else {
         $suggestions[] = $variables['theme_hook_original'];
       }
 
-      // Only add the original theme hook if it wasn't a directly called
-      // suggestion.
       foreach ($suggestions as &$suggestion) {
         $template = strtr($suggestion, '_', '-') . $extension;
         $prefix = ($template == $current_template) ? 'x' : '*';