diff --git a/admin/tool/task/lib.php b/admin/tool/task/lib.php
index ae23257b904..fd89b906ad8 100644
--- a/admin/tool/task/lib.php
+++ b/admin/tool/task/lib.php
@@ -37,3 +37,13 @@ function tool_task_status_checks() : array {
     ];
 }
 
+/**
+ * Function used to handle mtrace by outputting the text to normal browser window.
+ *
+ * @param string $message Message to output
+ * @param string $eol End of line character
+ */
+function tool_task_mtrace_wrapper(string $message, string $eol): void {
+    $message = s($message);
+    echo $message . $eol;
+}
diff --git a/admin/tool/task/schedule_task.php b/admin/tool/task/schedule_task.php
index aabd3de70ea..84097ba0571 100644
--- a/admin/tool/task/schedule_task.php
+++ b/admin/tool/task/schedule_task.php
@@ -30,16 +30,6 @@ require('../../../config.php');
 
 require_once($CFG->libdir.'/cronlib.php');
 
-/**
- * Function used to handle mtrace by outputting the text to normal browser window.
- *
- * @param string $message Message to output
- * @param string $eol End of line character
- */
-function tool_task_mtrace_wrapper($message, $eol) {
-    echo s($message . $eol);
-}
-
 // Allow execution of single task. This requires login and has different rules.
 $taskname = required_param('task', PARAM_RAW_TRIMMED);
 
@@ -97,6 +87,7 @@ require_sesskey();
 
 // Prepare to handle output via mtrace.
 echo html_writer::start_tag('pre');
+require('lib.php');
 $CFG->mtrace_wrapper = 'tool_task_mtrace_wrapper';
 
 // Run the specified task (this will output an error if it doesn't exist).
diff --git a/lib/classes/task/manager.php b/lib/classes/task/manager.php
index 765fba2f726..24c236a8f30 100644
--- a/lib/classes/task/manager.php
+++ b/lib/classes/task/manager.php
@@ -1133,12 +1133,40 @@ class manager {
             $command = "{$phpbinary} {$scriptpath} {$taskarg}";
 
             // Execute it.
-            passthru($command);
+            self::passthru_via_mtrace($command);
         }
 
         return true;
     }
 
+    /**
+     * This behaves similar to passthru but filters every line via
+     * the mtrace function so it can be post processed.
+     *
+     * @param string $command to run
+     * @return void
+     */
+    public static function passthru_via_mtrace(string $command) {
+        $descriptorspec = [
+            0 => ['pipe', 'r'], // STDIN.
+            1 => ['pipe', 'w'], // STDOUT.
+            2 => ['pipe', 'w'], // STDERR.
+        ];
+        flush();
+        $process = proc_open($command, $descriptorspec, $pipes, realpath('./'), []);
+        if (is_resource($process)) {
+            while ($s = fgets($pipes[1])) {
+                mtrace($s, '');
+                flush();
+            }
+        }
+
+        fclose($pipes[0]);
+        fclose($pipes[1]);
+        fclose($pipes[2]);
+        proc_close($process);
+    }
+
     /**
      * For a given scheduled task record, this method will check to see if any overrides have
      * been applied in config and return a copy of the record with any overridden values.