diff --git a/lee/state_machine/core/src/program.rs b/lee/state_machine/core/src/program.rs
index c5949dcf..f7791e85 100644
--- a/lee/state_machine/core/src/program.rs
+++ b/lee/state_machine/core/src/program.rs
@@ -317,7 +317,7 @@ impl AccountPostState {
 pub type BlockValidityWindow = ValidityWindow<BlockId>;
 pub type TimestampValidityWindow = ValidityWindow<Timestamp>;
 
-#[derive(Clone, Copy, Serialize, Deserialize)]
+#[derive(Clone, Copy, Default, Serialize, Deserialize)]
 #[cfg_attr(
     any(feature = "host", test),
     derive(Debug, PartialEq, Eq, BorshSerialize, BorshDeserialize)
diff --git a/lee/state_machine/src/privacy_preserving_transaction/message.rs b/lee/state_machine/src/privacy_preserving_transaction/message.rs
index b2594912..9fafad9e 100644
--- a/lee/state_machine/src/privacy_preserving_transaction/message.rs
+++ b/lee/state_machine/src/privacy_preserving_transaction/message.rs
@@ -11,7 +11,7 @@ use crate::{AccountId, error::LeeError};
 
 const PREFIX: &[u8; 32] = b"/LEE/v0.3/Message/Privacy/\x00\x00\x00\x00\x00\x00";
 
-#[derive(Clone, PartialEq, Eq, BorshSerialize, BorshDeserialize)]
+#[derive(Clone, Default, PartialEq, Eq, BorshSerialize, BorshDeserialize)]
 pub struct Message {
     pub public_account_ids: Vec<AccountId>,
     pub nonces: Vec<Nonce>,