diff --git a/public/course/format/classes/local/cmactions.php b/public/course/format/classes/local/cmactions.php
index fe300b1008c..4458fa44384 100644
--- a/public/course/format/classes/local/cmactions.php
+++ b/public/course/format/classes/local/cmactions.php
@@ -16,9 +16,11 @@
 
 namespace core_courseformat\local;
 
-
+use core\exception\moodle_exception;
 use core_courseformat\sectiondelegatemodule;
+use core_text;
 use course_modinfo;
+
 /**
  * Course module course format actions.
  *
@@ -68,6 +70,7 @@ class cmactions extends baseactions {
      * @param int $cmid the course module id.
      * @param string $name the new name.
      * @return bool true if the course module was renamed, false otherwise.
+     * @throws moodle_exception If the name is too long
      */
     public function rename(int $cmid, string $name): bool {
         global $CFG, $DB;
@@ -79,8 +82,8 @@ class cmactions extends baseactions {
         if (empty($name)) {
             return false;
         }
-        if (\core_text::strlen($name) > 255) {
-            throw new \moodle_exception('maximumchars', 'moodle', '', 255);
+        if (core_text::strlen($name) > 1333) {
+            throw new moodle_exception('maximumchars', 'moodle', '', 1333);
         }
 
         // The name is stored in the activity instance record.
diff --git a/public/course/format/tests/local/cmactions_test.php b/public/course/format/tests/local/cmactions_test.php
index e7bc2847762..8d0a3a65377 100644
--- a/public/course/format/tests/local/cmactions_test.php
+++ b/public/course/format/tests/local/cmactions_test.php
@@ -65,7 +65,7 @@ final class cmactions_test extends \advanced_testcase {
 
         $cminfo = get_fast_modinfo($course)->get_cm($activity->cmid);
         if ($result) {
-            $this->assertEquals('New name', $cminfo->name);
+            $this->assertEquals($newname, $cminfo->name);
         } else {
             $this->assertEquals('Old name', $cminfo->name);
         }
@@ -84,7 +84,12 @@ final class cmactions_test extends \advanced_testcase {
                 'expectexception' => false,
             ],
             'Maximum length' => [
-                'newname' => str_repeat('a', 256),
+                'newname' => str_repeat('a', 1333),
+                'expected' => true,
+                'expectexception' => false,
+            ],
+            'Beyond maximum length' => [
+                'newname' => str_repeat('a', 1334),
                 'expected' => false,
                 'expectexception' => true,
             ],