diff --git a/init/do_mounts.c b/init/do_mounts.c
index 6af29da8889e..64d5e25a2cb5 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -120,7 +120,8 @@ static int __init fs_names_setup(char *str)
 static unsigned int __initdata root_delay;
 static int __init root_delay_setup(char *str)
 {
-	root_delay = simple_strtoul(str, NULL, 0);
+	if (kstrtouint(str, 0, &root_delay))
+		return 0;
 	return 1;
 }