diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index bdf7090b106dadb817ad924b09a2cafcc4fc26de..a2854f6e07430b0c84e24582e233388925a7ba0b 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1340,7 +1340,7 @@ static struct ctl_table vm_table[] = {
 	{
 		.procname	= "dirtytime_expire_seconds",
 		.data		= &dirtytime_expire_interval,
-		.maxlen		= sizeof(dirty_expire_interval),
+		.maxlen		= sizeof(dirtytime_expire_interval),
 		.mode		= 0644,
 		.proc_handler	= dirtytime_interval_handler,
 		.extra1		= &zero,