diff --git a/application/controllers/Caldav.php b/application/controllers/Caldav.php
index c6c83ccfd1..2e9d9257ed 100644
--- a/application/controllers/Caldav.php
+++ b/application/controllers/Caldav.php
@@ -365,6 +365,8 @@ public function disable_provider_sync(): void
 
             $this->providers_model->save($provider);
 
+            $this->appointments_model->clear_caldav_sync_ids($provider_id);
+
             json_response([
                 'success' => true,
             ]);