diff --git a/packages/gnome-shell/src/extensions/prefs.d.ts b/packages/gnome-shell/src/extensions/prefs.d.ts
index 10d1693..8649890 100644
--- a/packages/gnome-shell/src/extensions/prefs.d.ts
+++ b/packages/gnome-shell/src/extensions/prefs.d.ts
@@ -26,7 +26,7 @@ export class ExtensionPreferences extends ExtensionBase {
      *
      * @param {Adw.PreferencesWindow} window - the preferences window
      */
-    fillPreferencesWindow(window: Adw.PreferencesWindow): Promise<void>;
+    fillPreferencesWindow(window: Adw.PreferencesWindow): Promise<void> | void;
 }
 
 export declare const gettext: TranslationFunctions['gettext'];