diff --git a/src/data_structures/src/byte_reader.cairo b/src/data_structures/src/byte_reader.cairo
index f3194a19..c84a5af1 100644
--- a/src/data_structures/src/byte_reader.cairo
+++ b/src/data_structures/src/byte_reader.cairo
@@ -3,8 +3,8 @@ use super::bit_array::{one_shift_left_bytes_felt252, one_shift_left_bytes_u128};
 
 #[derive(Copy, Clone, Drop)]
 pub struct ByteReaderState<T> {
-    pub data: @T,
-    pub index: usize,
+    pub(crate) data: @T,
+    index: usize,
 }
 
 pub trait ByteReader<T> {
diff --git a/src/data_structures/src/tests/byte_reader_test.cairo b/src/data_structures/src/tests/byte_reader_test.cairo
index 04998bfc..a35305b3 100644
--- a/src/data_structures/src/tests/byte_reader_test.cairo
+++ b/src/data_structures/src/tests/byte_reader_test.cairo
@@ -468,9 +468,9 @@ fn test_clone_byte_array_reader() {
     let mut rd1 = ba.reader();
     let mut rd2 = rd1.clone();
     let a = rd1.read_u128().unwrap();
-    assert!(rd1.index != rd2.index, "indicies equal");
+    assert!(rd1.len() != rd2.len(), "indices equal");
     let b = rd2.read_u128().unwrap();
-    assert!(rd1.index == rd2.index, "indicies not equal");
+    assert!(rd1.len() == rd2.len(), "indices not equal");
     assert!(a == b, "copy ByteArrayReader failed");
 }
 
@@ -481,9 +481,9 @@ fn test_clone_array_of_bytes_reader() {
     let mut rd1 = ba.reader();
     let mut rd2 = rd1.clone();
     let a = rd1.read_u128().unwrap();
-    assert!(rd1.index != rd2.index, "indicies equal");
+    assert!(rd1.len() != rd2.len(), "indices equal");
     let b = rd2.read_u128().unwrap();
-    assert!(rd1.index == rd2.index, "indicies not equal");
+    assert!(rd1.len() == rd2.len(), "indices not equal");
     assert!(a == b, "copy ByteArrayReader failed");
 }