diff --git a/drivers/serial/8250_pnp.c b/drivers/serial/8250_pnp.c
index ad0755919bcc..1de098e75497 100644
--- a/drivers/serial/8250_pnp.c
+++ b/drivers/serial/8250_pnp.c
@@ -439,7 +439,8 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 	}
 
 	memset(&port, 0, sizeof(struct uart_port));
-	port.irq = pnp_irq(dev, 0);
+	if (pnp_irq_valid(dev, 0))
+		port.irq = pnp_irq(dev, 0);
 	if (pnp_port_valid(dev, 0)) {
 		port.iobase = pnp_port_start(dev, 0);
 		port.iotype = UPIO_PORT;