diff --git a/audio.go b/audio.go
index 990c036..00db7c9 100644
--- a/audio.go
+++ b/audio.go
@@ -235,7 +235,6 @@ func (audio *Audio) init() error {
 		"ffmpeg",
 		"-i", audio.filename,
 		"-f", audio.format,
-		"-acodec", fmt.Sprintf("pcm_%s", audio.format),
 		"-ar", fmt.Sprintf("%d", audio.samplerate),
 		"-ac", fmt.Sprintf("%d", audio.channels),
 		"-map", fmt.Sprintf("0:a:%d", audio.stream),
diff --git a/audiowriter.go b/audiowriter.go
index 822fd37..4266445 100644
--- a/audiowriter.go
+++ b/audiowriter.go
@@ -112,7 +112,6 @@ func (writer *AudioWriter) init() error {
 		"-y", // overwrite output file if it exists.
 		"-loglevel", "quiet",
 		"-f", writer.format,
-		"-acodec", fmt.Sprintf("pcm_%s", writer.format),
 		"-ar", fmt.Sprintf("%d", writer.samplerate),
 		"-ac", fmt.Sprintf("%d", writer.channels),
 		"-i", "-", // The input comes from stdin.
diff --git a/microphone.go b/microphone.go
index 0cb4808..9b72503 100644
--- a/microphone.go
+++ b/microphone.go
@@ -210,7 +210,6 @@ func (mic *Microphone) init() error {
 		"-f", micDeviceName,
 		"-i", mic.name,
 		"-f", mic.format,
-		"-acodec", fmt.Sprintf("pcm_%s", mic.format),
 		"-ar", fmt.Sprintf("%d", mic.samplerate),
 		"-ac", fmt.Sprintf("%d", mic.channels),
 		"-",