diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 1a266a10d4cf..424436cb501e 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -59,7 +59,7 @@ static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
 	if (argv->v_nmembs == 0)
 		return 0;
 
-	if (argv->v_size > PAGE_SIZE)
+	if ((size_t)argv->v_size > PAGE_SIZE)
 		return -EINVAL;
 
 	/*