diff --git a/phpBB/includes/cron/tasks/core/prune_all_forums.php b/phpBB/includes/cron/tasks/core/prune_all_forums.php
index ebd09cbade..6d39fe6a15 100644
--- a/phpBB/includes/cron/tasks/core/prune_all_forums.php
+++ b/phpBB/includes/cron/tasks/core/prune_all_forums.php
@@ -63,6 +63,6 @@ class cron_task_core_prune_all_forums extends cron_task_base
 	public function is_runnable()
 	{
 		global $config;
-		return !!$config['use_system_cron'];
+		return (bool) $config['use_system_cron'];
 	}
 }
diff --git a/phpBB/includes/cron/tasks/core/tidy_warnings.php b/phpBB/includes/cron/tasks/core/tidy_warnings.php
index 4d70f3dc3d..6ef6a17fab 100644
--- a/phpBB/includes/cron/tasks/core/tidy_warnings.php
+++ b/phpBB/includes/cron/tasks/core/tidy_warnings.php
@@ -49,7 +49,7 @@ class cron_task_core_tidy_warnings extends cron_task_base
 	public function is_runnable()
 	{
 		global $config;
-		return !!$config['warnings_expire_days'];
+		return (bool) $config['warnings_expire_days'];
 	}
 
 	/**