diff --git a/crates/etl/src/lib.rs b/crates/etl/src/lib.rs
index 57db6473df..3f978fabee 100644
--- a/crates/etl/src/lib.rs
+++ b/crates/etl/src/lib.rs
@@ -21,6 +21,9 @@ use std::{
     path::{Path, PathBuf},
 };
 
+/// Key len and Value len encode use [`usize::to_be_bytes()`] the length is 8.
+const KV_LEN: usize = 8;
+
 use rayon::prelude::*;
 use reth_db_api::table::{Compress, Encode, Key, Value};
 use tempfile::{NamedTempFile, TempDir};
@@ -256,8 +259,8 @@ impl EtlFile {
             return Ok(None)
         }
 
-        let mut buffer_key_length = [0; 8];
-        let mut buffer_value_length = [0; 8];
+        let mut buffer_key_length = [0; KV_LEN];
+        let mut buffer_value_length = [0; KV_LEN];
 
         self.file.read_exact(&mut buffer_key_length)?;
         self.file.read_exact(&mut buffer_value_length)?;