diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 08b48bbf9f4b2d3c65cf18045ff90c1465c9787f..faf4e189fe423179cb0261e77a3519a2a2b1c03e 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -523,6 +523,7 @@ int watchdog_dev_register(struct watchdog_device *watchdog)
 	int err, devno;
 
 	if (watchdog->id == 0) {
+		old_wdd = watchdog;
 		watchdog_miscdev.parent = watchdog->parent;
 		err = misc_register(&watchdog_miscdev);
 		if (err != 0) {
@@ -531,9 +532,9 @@ int watchdog_dev_register(struct watchdog_device *watchdog)
 			if (err == -EBUSY)
 				pr_err("%s: a legacy watchdog module is probably present.\n",
 					watchdog->info->identity);
+			old_wdd = NULL;
 			return err;
 		}
-		old_wdd = watchdog;
 	}
 
 	/* Fill in the data structures */