diff --git a/drivers/staging/comedi/drivers/vmk80xx.c b/drivers/staging/comedi/drivers/vmk80xx.c
index 65dc6c51037e30edf30b1ad7e0d6eea7c0390e86..7956abcbae22bfdd2294b1220d892763bd431b3a 100644
--- a/drivers/staging/comedi/drivers/vmk80xx.c
+++ b/drivers/staging/comedi/drivers/vmk80xx.c
@@ -667,6 +667,9 @@ static int vmk80xx_find_usb_endpoints(struct comedi_device *dev)
 	if (!devpriv->ep_rx || !devpriv->ep_tx)
 		return -ENODEV;
 
+	if (!usb_endpoint_maxp(devpriv->ep_rx) || !usb_endpoint_maxp(devpriv->ep_tx))
+		return -EINVAL;
+
 	return 0;
 }