diff --git a/lib/Cron/Workers/SingleInstanceSimpleWorker.php b/lib/Cron/Workers/SingleInstanceSimpleWorker.php
index 481aaed3c0..e4ce1f8d89 100644
--- a/lib/Cron/Workers/SingleInstanceSimpleWorker.php
+++ b/lib/Cron/Workers/SingleInstanceSimpleWorker.php
@@ -48,12 +48,12 @@ abstract class SingleInstanceSimpleWorker extends SimpleWorker {
     return false;
   }
 
-  function startProgress(ScheduledTask $task) {
+  private function startProgress(ScheduledTask $task) {
     $task->meta = array_merge($task->getMeta(), ['in_progress' => true]);
     $task->save();
   }
 
-  function stopProgress(ScheduledTask $task) {
+  private function stopProgress(ScheduledTask $task) {
     $task->meta = array_merge($task->getMeta(), ['in_progress' => null]);
     $task->save();
   }
diff --git a/tests/integration/Cron/Workers/SingleInstanceSimpleWorkerTest.php b/tests/integration/Cron/Workers/SingleInstanceSimpleWorkerTest.php
index 99efe7de8b..1983ca50ce 100644
--- a/tests/integration/Cron/Workers/SingleInstanceSimpleWorkerTest.php
+++ b/tests/integration/Cron/Workers/SingleInstanceSimpleWorkerTest.php
@@ -21,8 +21,7 @@ class SingleInstanceSimpleWorkerTest extends \MailPoetTest {
     $task = $this->createScheduledTask();
     expect(empty($task->getMeta()['in_progress']))->equals(true);
     expect($this->worker->processTask($task))->equals(true);
-    $this->worker->startProgress($task);
-    expect(empty($task->getMeta()['in_progress']))->equals(false);
+    $task->meta = ['in_progress' => true];
     expect($this->worker->processTask($task))->equals(false);
   }