diff --git a/sound/drivers/serial-u16550.c b/sound/drivers/serial-u16550.c
index 3c28961091b1..cc9c325df910 100644
--- a/sound/drivers/serial-u16550.c
+++ b/sound/drivers/serial-u16550.c
@@ -846,6 +846,12 @@ static int snd_serial_probe(struct platform_device *devptr)
 	int err;
 	int dev = devptr->id;
 
+	if (dev < 0 || dev >= SNDRV_CARDS) {
+		dev_warn(&devptr->dev,
+			 "Invalid card index %d, using default 0\n", dev);
+		dev = 0;
+	}
+
 	switch (adaptor[dev]) {
 	case SNDRV_SERIAL_SOUNDCANVAS:
 		ins[dev] = 1;