diff --git a/types/moment-jalaali/index.d.ts b/types/moment-jalaali/index.d.ts
index a9c1d0f42d..e6fc2a6488 100644
--- a/types/moment-jalaali/index.d.ts
+++ b/types/moment-jalaali/index.d.ts
@@ -15,6 +15,12 @@ declare module 'moment' {
          * Use persian digits as decribed by unicode
          */
         usePersianDigits?: boolean;
+        /**
+         * use dialect option to change usePersian dialect, available options are:
+         *      persian: default dialect(امرداد، آدینه، ...)
+         *      persian-modern: modern dialect(مرداد، جمعه، ...)
+         */
+        dialect?: 'persian' | 'persian-modern';
     }
 
     /**