diff --git a/src/main.rs b/src/main.rs
index af95b0c..cd70834 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,7 +5,6 @@ use rust_util::{
         print_message,
         MessageType,
     },
-    util_io::*,
 };
 use std::{
     fs::File,
@@ -133,7 +132,7 @@ KECCAK-224, KECCAK-256, KECCAK-384, KECCAK-512, SM3
 }
 
 fn read_file_full(file_name: &str) -> XResult<Vec<u8>> {
-    let mut buf: [u8; DEFAULT_BUF_SIZE] = [0u8; DEFAULT_BUF_SIZE];
+    let mut buf: [u8; BUFF_SIZE] = [0u8; BUFF_SIZE];
     let mut f = File::open(file_name)?;
     let file_len = f.metadata()?.len();
     let mut ret: Vec<u8> = Vec::new();