diff --git a/src/tests/repeat.rs b/src/tests/repeat.rs
index 038e2c1..552041f 100644
--- a/src/tests/repeat.rs
+++ b/src/tests/repeat.rs
@@ -8,9 +8,7 @@ fn list_test<T: Value + Send + Sync + Debug, N: Unsigned + Debug>(val: T) {
         let fast = List::<T, N>::repeat(val.clone(), n).unwrap();
         let slow = List::<T, N>::repeat_slow(val.clone(), n).unwrap();
         assert_eq!(fast, slow);
-        let fast_root = fast.tree_hash_root();
-        let slow_root = slow.tree_hash_root();
-        assert_eq!(fast_root, slow_root);
+        assert_eq!(fast.tree_hash_root(), slow.tree_hash_root());
     }
 }
 
diff --git a/src/tree.rs b/src/tree.rs
index 1268d55..2443573 100644
--- a/src/tree.rs
+++ b/src/tree.rs
@@ -531,7 +531,6 @@ impl<T: Value + Send + Sync> Tree<T> {
     pub fn tree_hash(&self) -> Hash256 {
         match self {
             Self::Leaf(Leaf { hash, value }) => {
-                // FIXME(sproul): upgradeable RwLock?
                 let read_lock = hash.upgradable_read();
                 let existing_hash = *read_lock;