diff --git a/sys/dev/sound/midi/midi.c b/sys/dev/sound/midi/midi.c
--- a/sys/dev/sound/midi/midi.c
+++ b/sys/dev/sound/midi/midi.c
@@ -421,7 +421,7 @@
 	int used;
 	char buf[MIDI_WSIZE];
 
-	retval = 0;
+	retval = EIO;
 	if (m == NULL)
 		goto err0;