diff --git a/src/hash_builder/mod.rs b/src/hash_builder/mod.rs
index 17a17a1..c9ab172 100644
--- a/src/hash_builder/mod.rs
+++ b/src/hash_builder/mod.rs
@@ -39,7 +39,7 @@ pub use value::{HashBuilderValue, HashBuilderValueRef};
 /// up, combining the hashes of child nodes and ultimately generating the root hash. The root hash
 /// can then be used to verify the integrity and authenticity of the trie's data by constructing and
 /// verifying Merkle proofs.
-#[derive(Debug, Default)]
+#[derive(Debug, Clone, Default)]
 #[allow(missing_docs)]
 pub struct HashBuilder {
     pub key: Nibbles,
diff --git a/src/proof/retainer.rs b/src/proof/retainer.rs
index fd4d50f..0c5d74f 100644
--- a/src/proof/retainer.rs
+++ b/src/proof/retainer.rs
@@ -6,7 +6,7 @@ use alloc::vec::Vec;
 
 /// Proof retainer is used to store proofs during merkle trie construction.
 /// It is intended to be used within the [`HashBuilder`](crate::HashBuilder).
-#[derive(Default, Debug)]
+#[derive(Default, Clone, Debug)]
 pub struct ProofRetainer {
     /// The nibbles of the target trie keys to retain proofs for.
     targets: Vec<Nibbles>,