diff --git a/src/formats.ts b/src/formats.ts
index 4222ad5..c379bdc 100644
--- a/src/formats.ts
+++ b/src/formats.ts
@@ -127,6 +127,7 @@ export enum SubtitleFileFormat {
   STL = "STL",
   WebVTT = "WebVTT",
   SRT = "SRT",
+  ASS = "ASS",
 }
 
 export enum SubtitleDisplayStandard {