diff --git a/drivers/char/rio/rio_linux.c b/drivers/char/rio/rio_linux.c
index 2e8a6eed34be59039c57fbb6151973b8c19c9c3d..ce81da5b2da9a20079cf46fe64eddcac546b1474 100644
--- a/drivers/char/rio/rio_linux.c
+++ b/drivers/char/rio/rio_linux.c
@@ -333,7 +333,7 @@ void rio_copy_to_card(void *from, void __iomem *to, int len)
 
 int rio_minor(struct tty_struct *tty)
 {
-	return tty->index + (tty->driver == rio_driver) ? 0 : 256;
+	return tty->index + ((tty->driver == rio_driver) ? 0 : 256);
 }
 
 static int rio_set_real_termios(void *ptr)