diff --git a/benches/smt-subtree.rs b/benches/smt-subtree.rs
index c469b14..df97f79 100644
--- a/benches/smt-subtree.rs
+++ b/benches/smt-subtree.rs
@@ -25,7 +25,7 @@ fn smt_subtree_even(c: &mut Criterion) {
                     let entries: Vec<(RpoDigest, Word)> = (0..pair_count)
                         .map(|n| {
                             // A single depth-8 subtree can have a maximum of 255 leaves.
-                            let leaf_index = (n / pair_count) * 255;
+                            let leaf_index = ((n as f64 / pair_count as f64) * 255.0) as u64;
                             let key = RpoDigest::new([
                                 generate_value(&mut seed),
                                 ONE,
@@ -47,6 +47,7 @@ fn smt_subtree_even(c: &mut Criterion) {
                         })
                         .collect();
                     leaves.sort();
+                    leaves.dedup_by_key(|leaf| leaf.0);
                     leaves
                 },
                 |leaves| {
diff --git a/src/merkle/smt/mod.rs b/src/merkle/smt/mod.rs
index c05bf9c..ca3c492 100644
--- a/src/merkle/smt/mod.rs
+++ b/src/merkle/smt/mod.rs
@@ -597,7 +597,7 @@ mod test {
 
         let entries: Vec<(RpoDigest, Word)> = (0..PAIR_COUNT)
             .map(|i| {
-                let leaf_index = u64::MAX / (i + 1);
+                let leaf_index = ((i as f64 / PAIR_COUNT as f64) * 255.0) as u64;
                 let key = RpoDigest::new([ONE, ONE, Felt::new(i), Felt::new(leaf_index)]);
                 let value = [ONE, ONE, ONE, Felt::new(i)];
                 (key, value)
@@ -606,7 +606,7 @@ mod test {
 
         let control = Smt::with_entries(entries.clone()).unwrap();
 
-        let leaves: Vec<(u64, RpoDigest)> = entries
+        let mut leaves: Vec<(u64, RpoDigest)> = entries
             .iter()
             .map(|(key, value)| {
                 let leaf = SmtLeaf::new_single(*key, *value);
@@ -615,6 +615,8 @@ mod test {
                 (col, hash)
             })
             .collect();
+        leaves.sort();
+        leaves.dedup_by_key(|leaf| leaf.0);
 
         let first_subtree = Smt::build_subtree(leaves, SMT_DEPTH);
         assert!(!first_subtree.is_empty());