diff --git a/drivers/char/watchdog/machzwd.c b/drivers/char/watchdog/machzwd.c
index 81fb3dec180f..4a328ba0d262 100644
--- a/drivers/char/watchdog/machzwd.c
+++ b/drivers/char/watchdog/machzwd.c
@@ -324,7 +324,7 @@ static int zf_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 			return put_user(0, p);
 
 		case WDIOC_KEEPALIVE:
-			zf_ping(NULL);
+			zf_ping(0);
 			break;
 
 		default: