diff --git a/sound/drivers/mts64.c b/sound/drivers/mts64.c
index d3bc9e8c407d..f0d34cf70c3e 100644
--- a/sound/drivers/mts64.c
+++ b/sound/drivers/mts64.c
@@ -815,6 +815,9 @@ static void snd_mts64_interrupt(void *private)
 	u8 status, data;
 	struct snd_rawmidi_substream *substream;
 
+	if (!mts)
+		return;
+
 	spin_lock(&mts->lock);
 	ret = mts64_read(mts->pardev->port);
 	data = ret & 0x00ff;