diff --git a/drivers/staging/comedi/drivers/addi_apci_3xxx.c b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
index 82c22110f128..be1f6133ff1c 100644
--- a/drivers/staging/comedi/drivers/addi_apci_3xxx.c
+++ b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
@@ -787,6 +787,8 @@ static int apci3xxx_auto_attach(struct comedi_device *dev,
 
 	dev->iobase = pci_resource_start(pcidev, 2);
 	dev->mmio = pci_ioremap_bar(pcidev, 3);
+	if (!dev->mmio)
+		return -ENOMEM;
 
 	if (pcidev->irq > 0) {
 		ret = request_irq(pcidev->irq, apci3xxx_irq_handler,