diff --git a/whisper/utils.py b/whisper/utils.py
index 9b9b138..e793027 100644
--- a/whisper/utils.py
+++ b/whisper/utils.py
@@ -313,4 +313,11 @@ def get_writer(
 
         return write_all
 
-    return writers[output_format](output_dir)
+    writer_funcs = []
+    for format in output_format.split(','):
+        if format in writers:
+            writer_funcs.append(writers[format])
+        else:
+            raise ValueError(f"Output format '{format}' is not supported.")
+
+    return lambda result, file: [writer(output_dir)(result, file) for writer in writer_funcs]