diff --git a/AaxDecrypter/AaxcDownloadConverter.cs b/AaxDecrypter/AaxcDownloadConverter.cs
index f1acc9f8..f7dc13ef 100644
--- a/AaxDecrypter/AaxcDownloadConverter.cs
+++ b/AaxDecrypter/AaxcDownloadConverter.cs
@@ -175,7 +175,7 @@ namespace AaxDecrypter
 
         public bool Step3_DownloadAndCombine()
         {
-            OutputFormat format = OutputFormat.Mp3;
+            OutputFormat format = OutputFormat.Mp4a;
 
             DecryptProgressUpdate?.Invoke(this, int.MaxValue);