diff --git a/core/modules/system/src/Tests/Theme/EnginePhpTemplateTest.php b/core/modules/system/src/Tests/Theme/EngineNyanCatTest.php
similarity index 62%
rename from core/modules/system/src/Tests/Theme/EnginePhpTemplateTest.php
rename to core/modules/system/src/Tests/Theme/EngineNyanCatTest.php
index 37ab343966a55cd2bb0f436b8a1647f0bcb1e86a..bfaa1bb0d0fa9b783134c1edfca478f678b638f2 100644
--- a/core/modules/system/src/Tests/Theme/EnginePhpTemplateTest.php
+++ b/core/modules/system/src/Tests/Theme/EngineNyanCatTest.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * Contains \Drupal\system\Tests\Theme\EnginePhpTemplateTest.
+ * Contains \Drupal\system\Tests\Theme\EngineNyanCatTest.
  */
 
 namespace Drupal\system\Tests\Theme;
@@ -10,11 +10,11 @@
 use Drupal\simpletest\WebTestBase;
 
 /**
- * Tests theme functions with PHPTemplate.
+ * Tests the multi theme engine support.
  *
  * @group Theme
  */
-class EnginePhpTemplateTest extends WebTestBase {
+class EngineNyanCatTest extends WebTestBase {
 
   /**
    * Modules to enable.
@@ -25,7 +25,7 @@ class EnginePhpTemplateTest extends WebTestBase {
 
   protected function setUp() {
     parent::setUp();
-    \Drupal::service('theme_handler')->install(array('test_theme_phptemplate'));
+    \Drupal::service('theme_handler')->install(array('test_theme_nyan_cat_engine'));
   }
 
   /**
@@ -33,10 +33,10 @@ protected function setUp() {
    */
   function testTemplateOverride() {
     $this->config('system.theme')
-      ->set('default', 'test_theme_phptemplate')
+      ->set('default', 'test_theme_nyan_cat_engine')
       ->save();
     $this->drupalGet('theme-test/template-test');
-    $this->assertText('Success: Template overridden with PHPTemplate theme.', 'Template overridden by PHPTemplate file.');
+    $this->assertText('Success: Template overridden with Nyan Cat theme. All of them', 'Template overridden by Nyan Cat file.');
   }
 
 }
diff --git a/core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.engine b/core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.engine
new file mode 100644
index 0000000000000000000000000000000000000000..a1da728c2e918f9217e73aa2f9a51ce420d21806
--- /dev/null
+++ b/core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.engine
@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * @file
+ * Handles integration of Nyan cat templates because we love kittens.
+ */
+
+use Drupal\Core\Extension\Extension;
+
+/**
+ * Implements hook_init().
+ */
+function nyan_cat_init(Extension $theme) {
+  $theme->load();
+}
+
+/**
+ * Implements hook_theme().
+ */
+function nyan_cat_theme($existing, $type, $theme, $path) {
+  $templates = drupal_find_theme_functions($existing, array($theme));
+  $templates += drupal_find_theme_templates($existing, '.nyan-cat.html', $path);
+  return $templates;
+}
+
+/**
+ * Implements hook_extension().
+ */
+function nyan_cat_extension() {
+  return '.nyan-cat.html';
+}
+
+/**
+ * Implements hook_render_template().
+ *
+ * @param string $template_file
+ *   The filename of the template to render.
+ * @param mixed[] $variables
+ *   A keyed array of variables that will appear in the output.
+ *
+ * @return string
+ *   The output generated by the template.
+ */
+function nyan_cat_render_template($template_file, $variables) {
+  $output = str_replace('div', 'nyancat', file_get_contents(\Drupal::root() . '/' . $template_file));
+  foreach ($variables as $key => $variable) {
+    if (strpos($output, '9' . $key) !== FALSE) {
+      $output = str_replace('9' . $key, theme_render_and_autoescape($variable), $output);
+    }
+  }
+  return $output;
+}
diff --git a/core/themes/engines/phptemplate/phptemplate.info.yml b/core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.info.yml
similarity index 76%
rename from core/themes/engines/phptemplate/phptemplate.info.yml
rename to core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.info.yml
index 2bea7a07c69bb56fb86b33aa08dd6659e4802051..342191c6e2552ad92a066e0b0c1d9b98798699e1 100644
--- a/core/themes/engines/phptemplate/phptemplate.info.yml
+++ b/core/modules/system/tests/themes/engines/nyan_cat/nyan_cat.info.yml
@@ -1,5 +1,5 @@
 type: theme_engine
-name: PHPTemplate
+name: Nyan cat
 core: 8.x
 version: VERSION
 package: Core
diff --git a/core/modules/system/tests/themes/test_theme_nyan_cat_engine/test_theme_nyan_cat_engine.info.yml b/core/modules/system/tests/themes/test_theme_nyan_cat_engine/test_theme_nyan_cat_engine.info.yml
new file mode 100644
index 0000000000000000000000000000000000000000..a911bd05714b35a0d0fa8f60024b495b8cf60144
--- /dev/null
+++ b/core/modules/system/tests/themes/test_theme_nyan_cat_engine/test_theme_nyan_cat_engine.info.yml
@@ -0,0 +1,6 @@
+name: 'Test theme for Nyan Cat engine'
+type: theme
+description: 'Theme for testing the theme system with the Nyan Cat theme engine'
+version: VERSION
+core: 8.x
+engine: nyan_cat
diff --git a/core/modules/system/tests/themes/test_theme_nyan_cat_engine/test_theme_nyan_cat_engine.theme b/core/modules/system/tests/themes/test_theme_nyan_cat_engine/test_theme_nyan_cat_engine.theme
new file mode 100644
index 0000000000000000000000000000000000000000..5b69a12b557814e1f90ab1f38c8abf67358f412d
--- /dev/null
+++ b/core/modules/system/tests/themes/test_theme_nyan_cat_engine/test_theme_nyan_cat_engine.theme
@@ -0,0 +1,8 @@
+<?php
+
+/**
+ * Implements hook_preprocess_theme_test_template_test().
+ */
+function test_theme_nyan_cat_engine_preprocess_theme_test_template_test(&$variables) {
+  $variables['kittens'] = 'All of them';
+}
diff --git a/core/modules/system/tests/themes/test_theme_nyan_cat_engine/theme_test.template_test.nyan-cat.html b/core/modules/system/tests/themes/test_theme_nyan_cat_engine/theme_test.template_test.nyan-cat.html
new file mode 100644
index 0000000000000000000000000000000000000000..cb21cb5fd82e3fb08732af184fe47416ccca4311
--- /dev/null
+++ b/core/modules/system/tests/themes/test_theme_nyan_cat_engine/theme_test.template_test.nyan-cat.html
@@ -0,0 +1 @@
+Success: Template overridden with Nyan Cat theme. 9kittens
diff --git a/core/modules/system/tests/themes/test_theme_phptemplate/node--1.tpl.php b/core/modules/system/tests/themes/test_theme_phptemplate/node--1.tpl.php
deleted file mode 100644
index 81974cedaed6aada4002178908121b7fa677aaff..0000000000000000000000000000000000000000
--- a/core/modules/system/tests/themes/test_theme_phptemplate/node--1.tpl.php
+++ /dev/null
@@ -1,4 +0,0 @@
-<?php
-  // node--1.tpl.php - Dummy file for finding the template
-?>
-Node Content Dummy
diff --git a/core/modules/system/tests/themes/test_theme_phptemplate/test_theme_phptemplate.info.yml b/core/modules/system/tests/themes/test_theme_phptemplate/test_theme_phptemplate.info.yml
deleted file mode 100644
index da076b1f80a9d1f0459d1d9177efc5ea70f5db69..0000000000000000000000000000000000000000
--- a/core/modules/system/tests/themes/test_theme_phptemplate/test_theme_phptemplate.info.yml
+++ /dev/null
@@ -1,6 +0,0 @@
-name: 'Test theme PHPTemplate'
-type: theme
-description: 'Theme for testing the theme system with the PHPTemplate engine'
-version: VERSION
-core: 8.x
-engine: phptemplate
diff --git a/core/modules/system/tests/themes/test_theme_phptemplate/test_theme_phptemplate.theme b/core/modules/system/tests/themes/test_theme_phptemplate/test_theme_phptemplate.theme
deleted file mode 100644
index b3d9bbc7f3711e882119cd6b3af051245d859d04..0000000000000000000000000000000000000000
--- a/core/modules/system/tests/themes/test_theme_phptemplate/test_theme_phptemplate.theme
+++ /dev/null
@@ -1 +0,0 @@
-<?php
diff --git a/core/modules/system/tests/themes/test_theme_phptemplate/theme_test.template_test.tpl.php b/core/modules/system/tests/themes/test_theme_phptemplate/theme_test.template_test.tpl.php
deleted file mode 100644
index 86ef138354eb3da9ffefd3f6bc741ba0d054c5bd..0000000000000000000000000000000000000000
--- a/core/modules/system/tests/themes/test_theme_phptemplate/theme_test.template_test.tpl.php
+++ /dev/null
@@ -1,2 +0,0 @@
-<!-- Output for Theme API test -->
-<?php print 'Success: Template overridden with PHPTemplate theme.'; ?>
diff --git a/core/themes/engines/phptemplate/phptemplate.engine b/core/themes/engines/phptemplate/phptemplate.engine
deleted file mode 100644
index 232f78d343ef02e53a86ca835dffc0e36ca0f80a..0000000000000000000000000000000000000000
--- a/core/themes/engines/phptemplate/phptemplate.engine
+++ /dev/null
@@ -1,58 +0,0 @@
-<?php
-
-/**
- * @file
- * Handles integration of PHP templates with the Drupal theme system.
- */
-
-use Drupal\Core\Extension\Extension;
-
-/**
- * Implements hook_init().
- */
-function phptemplate_init(Extension $theme) {
-  $theme->load();
-}
-
-/**
- * Implements hook_theme().
- */
-function phptemplate_theme($existing, $type, $theme, $path) {
-  $templates = drupal_find_theme_functions($existing, array($theme));
-  $templates += drupal_find_theme_templates($existing, '.tpl.php', $path);
-  return $templates;
-}
-
-/**
- * Implements hook_extension().
- */
-function phptemplate_extension() {
-  return '.tpl.php';
-}
-
-/**
- * Implements hook_render_template().
- *
- * Renders a system default template, which is essentially a PHP template.
- *
- * @param $template_file
- *   The filename of the template to render.
- * @param $variables
- *   A keyed array of variables that will appear in the output.
- *
- * @return
- *   The output generated by the template.
- */
-function phptemplate_render_template($template_file, $variables) {
-  // Extract the variables to a local namespace
-  extract($variables, EXTR_SKIP);
-
-  // Start output buffering
-  ob_start();
-
-  // Include the template file
-  include \Drupal::root() . '/' . $template_file;
-
-  // End buffering and return its contents
-  return ob_get_clean();
-}