diff --git a/course/lib.php b/course/lib.php
index 6ad742947df..d0cb0b39a93 100644
--- a/course/lib.php
+++ b/course/lib.php
@@ -3420,10 +3420,12 @@ function duplicate_module($course, $cm) {
     $rc = new restore_controller($backupid, $course->id,
             backup::INTERACTIVE_NO, backup::MODE_IMPORT, $USER->id, backup::TARGET_CURRENT_ADDING);
 
-    // Configure the plan.
+    // Make sure that the restore_general_groups setting is always enabled when duplicating an activity.
     $plan = $rc->get_plan();
     $groupsetting = $plan->get_setting('groups');
-    $groupsetting->set_value(true);
+    if (empty($groupsetting->get_value())) {
+        $groupsetting->set_value(true);
+    }
 
     $cmcontext = context_module::instance($cm->id);
     if (!$rc->execute_precheck()) {