diff --git a/drivers/usb/gadget/f_midi.c b/drivers/usb/gadget/f_midi.c
index 44858dc074d3..ef1bc7a174ef 100644
--- a/drivers/usb/gadget/f_midi.c
+++ b/drivers/usb/gadget/f_midi.c
@@ -644,7 +644,7 @@ static int f_midi_out_open(struct snd_rawmidi_substream *substream)
 {
 	struct f_midi *midi = substream->rmidi->private_data;
 
-	if (!substream->number >= MAX_PORTS)
+	if (substream->number >= MAX_PORTS)
 		return -EINVAL;
 
 	VDBG(midi, "%s()\n", __func__);