diff --git a/core/lib/Drupal/Core/CoreBundle.php b/core/lib/Drupal/Core/CoreBundle.php
index 00d49e2..b4b4290 100644
--- a/core/lib/Drupal/Core/CoreBundle.php
+++ b/core/lib/Drupal/Core/CoreBundle.php
@@ -367,7 +367,7 @@ protected function registerTwig(ContainerBuilder $container) {
         // @see http://drupal.org/node/1806538.
         'strict_variables' => FALSE,
         'debug' => settings()->get('twig_debug', FALSE),
-        'auto_reload' => settings()->get('twig_auto_reload', FALSE),
+        'auto_reload' => settings()->get('twig_auto_reload', NULL),
       ))
       ->addMethodCall('addExtension', array(new Definition('Drupal\Core\Template\TwigExtension')))
       // @todo Figure out what to do about debugging functions.
diff --git a/core/modules/system/lib/Drupal/system/Tests/Theme/TwigSettingsTest.php b/core/modules/system/lib/Drupal/system/Tests/Theme/TwigSettingsTest.php
index a41542b..003d61e 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Theme/TwigSettingsTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Theme/TwigSettingsTest.php
@@ -58,6 +58,12 @@ function testTwigDebugOverride() {
 
     // Check isDebug() via the Twig service container.
     $this->assertTrue(drupal_container()->get('twig')->isDebug(), 'Twig debug enabled.');
+    $this->assertTrue(drupal_container()->get('twig')->isAutoReload(), 'Twig automatic reloading is enabled when debug is enabled.');
+
+    // Override auto reload when debug is enabled.
+    $this->settingsSet('twig_auto_reload', FALSE);
+    $this->rebuildContainer();
+    $this->assertFalse(drupal_container()->get('twig')->isAutoReload(), 'Twig automatic reloading can be disabled when debug is enabled.');
 
     // Disable debug and check the service container again.
     $this->settingsSet('twig_debug', FALSE);
diff --git a/sites/default/default.settings.php b/sites/default/default.settings.php
index 095852a..660e9e7 100755
--- a/sites/default/default.settings.php
+++ b/sites/default/default.settings.php
@@ -286,7 +286,8 @@
 /**
  * Twig debugging:
  *
- * Displays debugging information in comments surrounding Twig template output.
+ * Display debugging information in comments surrounding Twig template output
+ * and automatically recompile templates whenever the source code changes.
  *
  * Not recommended in production environments (Default: FALSE).
  */
@@ -295,9 +296,11 @@
 /**
  * Twig auto-reload:
  *
- * Automatically reload Twig templates whenever the source code changes.
+ * Automatically recompile Twig templates whenever the source code changes. If
+ * you don't provide a value for twig_auto_reload, it will be determined based
+ * on the value of twig_debug.
  *
- * Not recommended in production environments (Default: FALSE).
+ * Not recommended in production environments (Default: NULL).
  */
 # $settings['twig_auto_reload'] = TRUE;