diff --git a/Cargo.toml b/Cargo.toml
index 1904bf0..bf783a2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,7 +28,7 @@ hex = "0.2"
 lazy_static = "0.2"
 serde_json = "1.0"
 serde_derive = "1.0"
-emerald-rs = "0.17"
+emerald-rs = "0.18"
 regex = "0.2"
 rustc-serialize = "0.3"
 hyper = "0.10"
diff --git a/src/cmd/arg_handlers.rs b/src/cmd/arg_handlers.rs
index 78aa171..e309cde 100644
--- a/src/cmd/arg_handlers.rs
+++ b/src/cmd/arg_handlers.rs
@@ -187,7 +187,7 @@ impl CmdExecutor {
             |mut f| f.read_to_string(&mut json),
         )?;
 
-        let kf = KeyFile::decode(json)?;
+        let kf = KeyFile::decode(&json)?;
         let st = self.storage_ctrl.get_keystore(&self.chain)?;
 
         match st.is_addr_exist(&kf.address) {
diff --git a/src/cmd/mod.rs b/src/cmd/mod.rs
index 84224ea..cdf04cd 100644
--- a/src/cmd/mod.rs
+++ b/src/cmd/mod.rs
@@ -146,11 +146,11 @@ impl CmdExecutor {
             let pass = request_passphrase()?;
             let pk = kf.decrypt_key(&pass)?;
 
-            let raw = self.sign_transaction(tr, pk)?;
+            let raw = self.sign_transaction(&tr, pk)?;
             match self.connector {
                 Some(ref conn) => {
                     tr.nonce = rpc::get_nonce(conn, &kf.address)?;
-                    self.send_transaction(raw)
+                    self.send_transaction(&raw)
                 }
                 None => {
                     println!("Signed transaction: ");
@@ -325,7 +325,7 @@ impl CmdExecutor {
     }
 
     /// Sign transaction with
-    fn sign_transaction(&self, tr: Transaction, pk: PrivateKey) -> Result<Vec<u8>, Error> {
+    fn sign_transaction(&self, tr: &Transaction, pk: PrivateKey) -> Result<Vec<u8>, Error> {
         if let Some(chain_id) = to_chain_id(&self.chain) {
             let raw = tr.to_signed_raw(pk, chain_id)?;
             Ok(raw)
@@ -334,10 +334,10 @@ impl CmdExecutor {
         }
     }
 
-    fn send_transaction(&self, raw: Vec<u8>) -> ExecResult<Error> {
+    fn send_transaction(&self, raw: &[u8]) -> ExecResult<Error> {
         match self.connector {
             Some(ref conn) => {
-                let tx_hash = rpc::send_transaction(conn, &raw)?;
+                let tx_hash = rpc::send_transaction(conn, raw)?;
                 println!("Tx hash: ");
                 println!("{}", tx_hash);
                 Ok(())
diff --git a/src/main.rs b/src/main.rs
index 0c7ba77..0a1ddab 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -34,7 +34,7 @@ use log::LogRecord;
 use std::env;
 use std::process::*;
 
-const USAGE: &'static str = include_str!("../usage.txt");
+const USAGE: &str = include_str!("../usage.txt");
 const VERSION: Option<&'static str> = option_env!("CARGO_PKG_VERSION");
 
 /// Get the current Emerald version.