diff --git a/contracts/mixnet/src/contract.rs b/contracts/mixnet/src/contract.rs
index cc2bd76d5c..484d07f480 100644
--- a/contracts/mixnet/src/contract.rs
+++ b/contracts/mixnet/src/contract.rs
@@ -336,6 +336,7 @@ pub fn migrate(deps: DepsMut, env: Env, _msg: MigrateMsg) -> Result<Response, Co
         pub minimum_gateway_pledge: Uint128,
         pub mixnode_rewarded_set_size: u32,
         pub mixnode_active_set_size: u32,
+        #[serde(default)]
         pub active_set_work_factor: u8,
     }
 
@@ -344,8 +345,11 @@ pub fn migrate(deps: DepsMut, env: Env, _msg: MigrateMsg) -> Result<Response, Co
         pub owner: Addr, // only the owner account can update state
         pub rewarding_validator_address: Addr,
         pub params: OldContractStateParams,
+        #[serde(default)]
         pub rewarding_interval_starting_block: u64,
+        #[serde(default)]
         pub latest_rewarding_interval_nonce: u32,
+        #[serde(default)]
         pub rewarding_in_progress: bool,
     }