diff --git a/crates/storage/db/benches/hash_keys.rs b/crates/storage/db/benches/hash_keys.rs
index 1807e6f4a6ec..275344749d0a 100644
--- a/crates/storage/db/benches/hash_keys.rs
+++ b/crates/storage/db/benches/hash_keys.rs
@@ -150,7 +150,7 @@ where
     let mut preload = strategy.new_tree(&mut runner).unwrap().current();
     let mut input = strategy.new_tree(&mut runner).unwrap().current();
 
-    let mut unique_keys = HashSet::new();
+    let mut unique_keys = HashSet::with_capacity(preload.len() + input.len());
     preload.retain(|(k, _)| unique_keys.insert(k.clone()));
     input.retain(|(k, _)| unique_keys.insert(k.clone()));