diff --git a/src/app_ui/sign.rs b/src/app_ui/sign.rs
index 09bfa1c..e38a503 100644
--- a/src/app_ui/sign.rs
+++ b/src/app_ui/sign.rs
@@ -41,7 +41,7 @@ use alloc::format;
 ///
 /// * `tx` - Transaction to be displayed for validation
 pub fn ui_display_tx(tx: &Transaction) -> Result<bool, AppSW> {
-    let value_str = tx.value.to_cfx_str().ok_or(AppSW::TxDisplayFail)?;
+    let value_str = tx.value.cfx_str().ok_or(AppSW::TxDisplayFail)?;
     let network = Network::from_network_id(tx.chain_id);
     let to_str = cfx_addr_encode(&*tx.to, network).map_err(|_e| AppSW::AddrDisplayFail)?;
     let data_str = format!("0x{}", hex::encode(tx.data.clone()).to_uppercase());
diff --git a/src/types/primitives.rs b/src/types/primitives.rs
index faaa7c4..b2d8117 100644
--- a/src/types/primitives.rs
+++ b/src/types/primitives.rs
@@ -12,7 +12,7 @@ construct_uint! {
 }
 
 impl U256 {
-    pub fn to_cfx_str(&self) -> Option<String> {
+    pub fn cfx_str(&self) -> Option<String> {
         let wei_str = self.to_string();
         let wei = BigDecimal::from_str(&wei_str).ok()?;
         let eth_conversion = BigDecimal::from_i64(10_i64.pow(18))?;