diff --git a/core/lib/Drupal/Core/Theme/ThemeManager.php b/core/lib/Drupal/Core/Theme/ThemeManager.php
index 7add727..5b37a70 100644
--- a/core/lib/Drupal/Core/Theme/ThemeManager.php
+++ b/core/lib/Drupal/Core/Theme/ThemeManager.php
@@ -13,7 +13,6 @@
 use Symfony\Component\HttpFoundation\RequestStack;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Template\Attribute;
-use Drupal\Component\Utility\SafeMarkup;
 
 /**
  * Provides the default implementation of a theme manager.
@@ -318,9 +317,9 @@ public function render($hook, array $variables) {
     $output = '';
     if (isset($info['function'])) {
       if (function_exists($info['function'])) {
-        // Theme functions do not render via the theme engine, so the output
-        // is not autoescaped. However, we can only presume that the theme
-        // function has been written correctly and that the markup is safe.
+        // Theme functions do not render via the theme engine, so the output is
+        // not autoescaped. However, we can only presume that the theme function
+        // has been written correctly and that the markup is safe.
         $output = SafeString::create($info['function']($variables));
       }
     }
diff --git a/core/modules/system/src/Tests/Theme/ThemeTest.php b/core/modules/system/src/Tests/Theme/ThemeTest.php
index 7d2704f..4697c2f 100644
--- a/core/modules/system/src/Tests/Theme/ThemeTest.php
+++ b/core/modules/system/src/Tests/Theme/ThemeTest.php
@@ -60,9 +60,9 @@ function testAttributeMerging() {
    * Test that _theme() returns expected data types.
    */
   function testThemeDataTypes() {
-    // theme_test_false is an implemented theme hook so \Drupal::theme() service should
-    // return a string or an object that implements SafeStringInterface, even though the
-    // theme function itself can return anything.
+    // theme_test_false is an implemented theme hook so \Drupal::theme() service
+    // should return a string or an object that implements SafeStringInterface,
+    // even though the theme function itself can return anything.
     $foos = array('null' => NULL, 'false' => FALSE, 'integer' => 1, 'string' => 'foo');
     foreach ($foos as $type => $example) {
       $output = \Drupal::theme()->render('theme_test_foo', array('foo' => $example));