diff --git a/idsig/src/hashtree.rs b/idsig/src/hashtree.rs
index 1ce2879..63f83ea 100644
--- a/idsig/src/hashtree.rs
+++ b/idsig/src/hashtree.rs
@@ -100,7 +100,7 @@
             // and split it.
             let prev = &levels[n - 1];
             let cur_and_prev = &mut hash_tree[cur.start..prev.end];
-            let (cur, prev) = cur_and_prev.split_at_mut(prev.start);
+            let (cur, prev) = cur_and_prev.split_at_mut(prev.start - cur.start);
             let mut cur = Cursor::new(cur);
             prev.chunks(block_size).for_each(|data| {
                 let h = hash_one_block(data, salt, block_size, algorithm);
@@ -200,7 +200,7 @@
     #[test]
     fn compare_with_golden_output() -> Result<()> {
         // The golden outputs are generated by using the `fsverity` utility.
-        let sizes = ["512", "4K", "1M", "10000000"];
+        let sizes = ["512", "4K", "1M", "10000000", "272629760"];
         for size in sizes.iter() {
             let input_name = format!("testdata/input.{}", size);
             let mut input = File::open(&input_name)?;