diff --git a/src/miner/mod.rs b/src/miner/mod.rs
index 5fa7f36..a364993 100644
--- a/src/miner/mod.rs
+++ b/src/miner/mod.rs
@@ -117,7 +117,7 @@ pub fn make_state<P: Patch>(genesis_accounts: Vec<(SecretKey, U256)>) -> MinerSt
                 value: balance,
                 input: Rc::new(Vec::new()),
                 nonce: U256::zero(),
-            }, HeaderParams::from(&genesis.header), &[]);
+            }, &HeaderParams::from(&genesis.header), &[]);
             let mut accounts = Vec::new();
             for account in vm.accounts() {
                 accounts.push(account.clone());
@@ -169,9 +169,9 @@ pub fn mine_one<P: Patch>(state: Arc<Mutex<MinerState>>, address: Address) {
 
     for transaction in transactions.clone() {
         let transaction_hash = transaction.rlp_hash();
-        let valid = state.stateful_mut().to_valid::<P>(transaction).unwrap();
+        let valid = state.stateful_mut().to_valid::<P>(&transaction).unwrap();
         let vm: SeqTransactionVM<P> = {
-            let vm = state.stateful_mut().call(valid, HeaderParams::from(&current_block.header),
+            let vm = state.stateful_mut().call(valid, &HeaderParams::from(&current_block.header),
                                &block_hashes);
             let mut accounts = Vec::new();
             for account in vm.accounts() {
diff --git a/src/rpc/serves.rs b/src/rpc/serves.rs
index 7b8f8c0..9d5c722 100644
--- a/src/rpc/serves.rs
+++ b/src/rpc/serves.rs
@@ -306,7 +306,7 @@ impl<P: 'static + Patch + Send> EthereumRPC for MinerEthereumRPC<P> {
         let (valid, transaction) = {
             let stateful = state.stateful();
             let transaction = to_signed_transaction(&state, transaction, &stateful)?;
-            let valid = stateful.to_valid::<P>(transaction.clone())?;
+            let valid = stateful.to_valid::<P>(&transaction.clone())?;
 
             (valid, transaction)
         };
@@ -324,7 +324,7 @@ impl<P: 'static + Patch + Send> EthereumRPC for MinerEthereumRPC<P> {
 
         {
             let stateful = state.stateful();
-            stateful.to_valid::<P>(transaction.clone())?;
+            stateful.to_valid::<P>(&transaction.clone())?;
         }
 
         let hash = state.append_pending_transaction(transaction);
@@ -343,7 +343,7 @@ impl<P: 'static + Patch + Send> EthereumRPC for MinerEthereumRPC<P> {
         let block = state.get_block_by_number(block);
 
         let vm: SeqTransactionVM<P> = stateful.call(
-            valid, HeaderParams::from(&block.header),
+            valid, &HeaderParams::from(&block.header),
             &state.get_last_256_block_hashes());
 
         Ok(Bytes(vm.out().into()))
@@ -360,7 +360,7 @@ impl<P: 'static + Patch + Send> EthereumRPC for MinerEthereumRPC<P> {
         let block = state.get_block_by_number(block);
 
         let vm: SeqTransactionVM<P> = stateful.call(
-            valid, HeaderParams::from(&block.header),
+            valid, &HeaderParams::from(&block.header),
             &state.get_last_256_block_hashes());
 
         Ok(Hex(vm.used_gas()))
@@ -600,9 +600,9 @@ impl<P: 'static + Patch + Send> DebugRPC for MinerDebugRPC<P> {
         let mut stateful: MemoryStateful<'static> = state.stateful_at(last_block.header.state_root);
         for other_transaction in &block.transactions {
             if other_transaction != &transaction {
-                let valid = stateful.to_valid::<P>(transaction.clone())?;
+                let valid = stateful.to_valid::<P>(&transaction.clone())?;
                 let _: SeqTransactionVM<P> =
-                    stateful.execute::<_, P>(valid, HeaderParams::from(&block.header), &last_hashes);
+                    stateful.execute::<_, P>(valid, &HeaderParams::from(&block.header), &last_hashes);
             } else {
                 break;
             }
diff --git a/src/rpc/util.rs b/src/rpc/util.rs
index 7d0a4f6..3304605 100644
--- a/src/rpc/util.rs
+++ b/src/rpc/util.rs
@@ -359,7 +359,7 @@ pub fn replay_transaction<P: Patch>(
     stateful: &MemoryStateful<'static>, transaction: Transaction, block: &Block,
     last_hashes: &[H256], config: &RPCTraceConfig
 ) -> Result<(Vec<RPCStep>, SeqTransactionVM<P>), Error> {
-    let valid = stateful.to_valid::<P>(transaction)?;
+    let valid = stateful.to_valid::<P>(&transaction)?;
     let mut vm = SeqTransactionVM::<P>::new(valid, HeaderParams::from(&block.header));
     let mut steps = Vec::new();
     let mut last_gas = Gas::zero();