diff --git a/lib/classes/task/manager.php b/lib/classes/task/manager.php
index b57fd17922f..ae9c59a240e 100644
--- a/lib/classes/task/manager.php
+++ b/lib/classes/task/manager.php
@@ -55,6 +55,11 @@ class manager {
      */
     const ADHOC_TASK_FAILED_RETENTION = 4 * WEEKSECS;
 
+    /**
+     * @var int Used for max retry.
+     */
+    const MAX_RETRY = 9;
+
     /**
      * @var array A cached queue of adhoc tasks
      */
@@ -236,7 +241,7 @@ class manager {
         }
 
         // Check if the task is allowed to be retried or not.
-        $record->attemptsavailable = $task->retry_until_success() ? null : 1;
+        $record->attemptsavailable = $task->retry_until_success() ? self::MAX_RETRY : 1;
 
         // Check if the same task is already scheduled.
         if ($checkforexisting && self::task_is_scheduled($task)) {
@@ -1128,7 +1133,7 @@ class manager {
         $task->set_pid();
         $task->set_next_run_time(time() + $delay);
         $task->set_fail_delay($delay);
-        if (!$task->retry_until_success() && $task->get_attempts_available() > 0) {
+        if ($task->get_attempts_available() > 0) {
             $task->set_attempts_available($task->get_attempts_available() - 1);
         }
         $record = self::record_from_adhoc_task($task);
diff --git a/lib/tests/task/adhoc_task_test.php b/lib/tests/task/adhoc_task_test.php
index 0a726f39f56..2bddaa067dc 100644
--- a/lib/tests/task/adhoc_task_test.php
+++ b/lib/tests/task/adhoc_task_test.php
@@ -164,7 +164,7 @@ class adhoc_task_test extends \advanced_testcase {
             return: 'attemptsavailable',
             conditions: ['id' => $taskid1]
         );
-        $this->assertNull(actual: $attemptsavailable);
+        $this->assertEquals(expected: manager::MAX_RETRY, actual: $attemptsavailable);
 
         // Get the task from the scheduler, execute it, and mark it as failed.
         $task = manager::get_next_adhoc_task(timestart: $now);
@@ -178,7 +178,7 @@ class adhoc_task_test extends \advanced_testcase {
             return: 'attemptsavailable',
             conditions: ['id' => $taskid1]
         );
-        $this->assertNull(actual: $attemptsavailable);
+        $this->assertEquals(expected: manager::MAX_RETRY - 1, actual: $attemptsavailable);
 
         // Create a no-retry adhoc task.
         $now = time();