diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index 56a83e4184c..9ad2ec5fc7b 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -17861,7 +17861,7 @@ class Notification extends EventTarget native "*Notification" {
 
   @DomName('Notification.requestPermission')
   @DocsEditable
-  static void requestPermission(NotificationPermissionCallback callback) native;
+  static void requestPermission([NotificationPermissionCallback callback]) native;
 
   @DomName('Notification.show')
   @DocsEditable
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index c482bd24cb1..f395d3668dd 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -19374,7 +19374,7 @@ class Notification extends EventTarget {
 
   @DomName('Notification.requestPermission')
   @DocsEditable
-  static void requestPermission(NotificationPermissionCallback callback) native "Notification_requestPermission_Callback";
+  static void requestPermission([NotificationPermissionCallback callback]) native "Notification_requestPermission_Callback";
 
   @DomName('Notification.show')
   @DocsEditable