diff --git a/animetosho2mks.py b/animetosho2mks.py
index fc5aaa9..dc375df 100755
--- a/animetosho2mks.py
+++ b/animetosho2mks.py
@@ -13,7 +13,11 @@ class SubtitleTrack:
 
     def _parse_filename(self):
         basename = self.filename.split(".")[0]
-        language = basename.split("_")[1]
+        try:
+            language = basename.split("_")[1]
+        except IndexError:
+            # older format
+            language = "eng"
 
         return language