diff --git a/README.md b/README.md
index 41c9433..af59a56 100644
--- a/README.md
+++ b/README.md
@@ -178,8 +178,8 @@ $video = $ffmpeg->open( 'video.mp4' );
 // Set an audio format
 $audio_format = new FFMpeg\Format\Audio\Mp3();
 
-// Extract the audio into a new file
-$video->save('audio.mp3');
+// Extract the audio into a new file as mp3
+$video->save($audio_format, 'audio.mp3');
 
 // Set the audio file
 $audio = $ffmpeg->open( 'audio.mp3' );