diff --git a/source/packages/com_mokosuitebackup/src/Controller/AjaxController.php b/source/packages/com_mokosuitebackup/src/Controller/AjaxController.php
index 0afdce73..af2b2695 100644
--- a/source/packages/com_mokosuitebackup/src/Controller/AjaxController.php
+++ b/source/packages/com_mokosuitebackup/src/Controller/AjaxController.php
@@ -89,11 +89,11 @@ class AjaxController extends BaseController
 	 *
 	 * Called by the full-screen backup screen after a successful backup so the
 	 * imminent server-side onExtensionBeforeUpdate / onExtensionBeforeUninstall
-	 * backup is skipped — it arms the same 10-minute throttle keys the system
-	 * plugin checks, preventing a duplicate backup when the update / uninstall
-	 * then proceeds. Arms BOTH keys so a single ack covers whichever action the
-	 * full-screen backup was fronting.
-	 * POST: task=ajax.preupdateAck
+	 * backup is skipped once — it sets a ONE-SHOT skip flag (keyed by the
+	 * `action` the backup was fronting) that plg_system_mokosuitebackup
+	 * consumes on the re-fired update/uninstall request, so exactly that one
+	 * action is not double-backed-up while later, distinct actions still are.
+	 * POST: task=ajax.preupdateAck&action=update|uninstall
 	 */
 	public function preupdateAck(): void
 	{