diff --git a/angular-translate/angular-translate.d.ts b/angular-translate/angular-translate.d.ts
index 1abb13ae8..ab4c1db5f 100644
--- a/angular-translate/angular-translate.d.ts
+++ b/angular-translate/angular-translate.d.ts
@@ -93,7 +93,7 @@ declare module angular.translate {
         storageKey(key: string): void; // JeroMiya - the library should probably return ITranslateProvider but it doesn't here
         useUrlLoader(url: string): ITranslateProvider;
         useStaticFilesLoader(options: IStaticFilesLoaderOptions): ITranslateProvider;
-        useLoader(loaderFactory: string, options: any): ITranslateProvider;
+        useLoader(loaderFactory: string, options?: any): ITranslateProvider;
         useLocalStorage(): ITranslateProvider;
         useCookieStorage(): ITranslateProvider;
         useStorage(storageFactory: any): ITranslateProvider;