diff --git a/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
index 978b0f4..8ea3f56 100644
--- a/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -1588,7 +1588,7 @@ function system_cron_settings() {
   $form['cron']['cron_safe_threshold'] = array(
     '#type' => 'select',
     '#title' => t('Run cron every'),
-    '#default_value' => variable_get('cron_safe_threshold', DRUPAL_CRON_DEFAULT_THRESHOLD),
+    '#default_value' => config('system.cron')->get('cron_safe_threshold'),
     '#options' => array(0 => t('Never')) + drupal_map_assoc(array(3600, 10800, 21600, 43200, 86400, 604800), 'format_interval'),
   );
 
diff --git a/core/modules/system/system.install b/core/modules/system/system.install
index 14d4853..c78e38d 100644
--- a/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -1761,6 +1761,14 @@ function system_update_8004() {
 }
 
 /**
+ * Upgrade cron variable system:
+ *  Remove cron_safe_threshold from variable table.
+ */
+function system_update_8005() {
+  variable_del('cron_safe_threshold');
+}
+
+/**
  * @} End of "defgroup updates-7.x-to-8.x"
  * The next series of updates should start at 9000.
  */
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 94fd3e0..24ec64e 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -11,11 +11,6 @@
 const DRUPAL_MAXIMUM_TEMP_FILE_AGE = 21600;
 
 /**
- * Default interval for automatic cron executions in seconds.
- */
-const DRUPAL_CRON_DEFAULT_THRESHOLD = 10800;
-
-/**
  * New users will be set to the default time zone at registration.
  */
 const DRUPAL_USER_TIMEZONE_DEFAULT = 0;
@@ -3515,7 +3510,7 @@ function system_run_automated_cron() {
   // If the site is not fully installed, suppress the automated cron run.
   // Otherwise it could be triggered prematurely by Ajax requests during
   // installation.
-  if (($threshold = variable_get('cron_safe_threshold', DRUPAL_CRON_DEFAULT_THRESHOLD)) > 0 && variable_get('install_task') == 'done') {
+  if (($threshold = config('system.cron')->get('cron_safe_threshold')) > 0 && variable_get('install_task') == 'done') {
     $cron_last = variable_get('cron_last', NULL);
     if (!isset($cron_last) || (REQUEST_TIME - $cron_last > $threshold)) {
       drupal_cron_run();
diff --git a/core/modules/system/system.test b/core/modules/system/system.test
index 9287d16..f057423 100644
--- a/core/modules/system/system.test
+++ b/core/modules/system/system.test
@@ -771,7 +771,9 @@ class CronRunTestCase extends DrupalWebTestCase {
     $cron_last = time();
     $cron_safe_threshold = 100;
     variable_set('cron_last', $cron_last);
-    variable_set('cron_safe_threshold', $cron_safe_threshold);
+    config('system.cron')
+      ->set('cron_safe_threshold', $cron_safe_threshold)
+      ->save();
     $this->drupalGet('');
     $this->assertTrue($cron_last == variable_get('cron_last', NULL), t('Cron does not run when the cron threshold is not passed.'));