diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index 7700dcfd27..1a3560dbb1 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -5254,7 +5254,7 @@ function page_footer($run_cron = true, $display_template = true, $exit_handler =
 
 	// Call cron-type script
 	$call_cron = false;
-	if (!defined('IN_CRON') && !$config['use_system_cron'] && $run_cron && !$config['board_disable'] && !$user->data['is_bot'] && !$cache->get('cron.lock_check'))
+	if (!defined('IN_CRON') && !$config['use_system_cron'] && $run_cron && !$config['board_disable'] && !$user->data['is_bot'] && !$cache->get('_cron.lock_check'))
 	{
 		$call_cron = true;
 		$time_now = (!empty($user->time_now) && is_int($user->time_now)) ? $user->time_now : time();
@@ -5286,7 +5286,7 @@ function page_footer($run_cron = true, $display_template = true, $exit_handler =
 		}
 		else
 		{
-			$cache->put('cron.lock_check', true, 300);
+			$cache->put('_cron.lock_check', true, 60);
 		}
 	}
 
diff --git a/phpBB/phpbb/avatar/driver/local.php b/phpBB/phpbb/avatar/driver/local.php
index 07b3ed59de..8888686b2d 100644
--- a/phpBB/phpbb/avatar/driver/local.php
+++ b/phpBB/phpbb/avatar/driver/local.php
@@ -154,7 +154,7 @@ class local extends \phpbb\avatar\driver\driver
 	*/
 	protected function get_avatar_list($user)
 	{
-		$avatar_list = ($this->cache == null) ? false : $this->cache->get('avatar_local_list');
+		$avatar_list = ($this->cache == null) ? false : $this->cache->get('_avatar_local_list');
 
 		if ($avatar_list === false)
 		{
@@ -192,7 +192,7 @@ class local extends \phpbb\avatar\driver\driver
 
 			if ($this->cache != null)
 			{
-				$this->cache->put('avatar_local_list', $avatar_list, 86400);
+				$this->cache->put('_avatar_local_list', $avatar_list, 86400);
 			}
 		}
 
diff --git a/phpBB/phpbb/cron/manager.php b/phpBB/phpbb/cron/manager.php
index 5c8ac04b77..079ce8107e 100644
--- a/phpBB/phpbb/cron/manager.php
+++ b/phpBB/phpbb/cron/manager.php
@@ -73,6 +73,7 @@ class manager
 	*/
 	public function find_one_ready_task()
 	{
+		shuffle($this->tasks);
 		foreach ($this->tasks as $task)
 		{
 			if ($task->is_ready())
diff --git a/phpBB/phpbb/version_helper.php b/phpBB/phpbb/version_helper.php
index 968a57428f..96386f6d04 100644
--- a/phpBB/phpbb/version_helper.php
+++ b/phpBB/phpbb/version_helper.php
@@ -239,7 +239,7 @@ class version_helper
 	*/
 	public function get_versions($force_update = false, $force_cache = false)
 	{
-		$cache_file = 'versioncheck_' . $this->host . $this->path . $this->file;
+		$cache_file = '_versioncheck_' . $this->host . $this->path . $this->file;
 
 		$info = $this->cache->get($cache_file);
 
diff --git a/tests/functional/prune_shadow_topic_test.php b/tests/functional/prune_shadow_topic_test.php
index 84f07e9802..f00303060d 100644
--- a/tests/functional/prune_shadow_topic_test.php
+++ b/tests/functional/prune_shadow_topic_test.php
@@ -129,8 +129,8 @@ class phpbb_functional_prune_shadow_topic_test extends phpbb_functional_test_cas
 		$result = $this->db->sql_query($sql);
 
 		$crawler = self::request('GET', "viewforum.php?f={$this->data['forums']['Prune Shadow']}&sid={$this->sid}");
-		$cron_link = $crawler->filter('img')->last()->attr('src');
-		$crawler = self::request('GET', $cron_link . "&sid={$this->sid}", array(), false);
+		$this->assertNotEmpty($crawler->filter('img')->last()->attr('src'));
+		self::request('GET', "cron.php?cron_type=cron.task.core.prune_shadow_topics&f={$this->data['forums']['Prune Shadow']}&sid={$this->sid}", array(), false);
 
 		$this->assert_forum_details($this->data['forums']['Prune Shadow'], array(
 			'forum_posts_approved'		=> 0,