diff --git a/bingus/src/bin_/bytes.rs b/bingus/src/bin_/bytes.rs
index c1498f2..c286c06 100644
--- a/bingus/src/bin_/bytes.rs
+++ b/bingus/src/bin_/bytes.rs
@@ -1,6 +1,6 @@
 use std::convert::Infallible;
 
-use rayon::iter::{IntoParallelIterator, ParallelIterator};
+use rayon::iter::{IntoParallelRefMutIterator, ParallelIterator};
 
 use crate::{Bendable, Bytes, IntoDataBytes, TryFromDataBytes};
 
@@ -23,8 +23,9 @@ impl TryFromDataBytes for Bytes {
 
 impl Bendable for Bytes {
     type Unit = u8;
-    fn map<F: Fn(&Self::Unit) -> Self::Unit + Sync>(self, f: F) -> Self {
-        self.into_par_iter().map(|e| f(&e)).collect()
+    fn map<F: Fn(&Self::Unit) -> Self::Unit + Sync>(mut self, f: F) -> Self {
+        self.par_iter_mut().for_each(|e| *e = f(e));
+        self
     }
     fn format() -> crate::Format {
         crate::Format::Binary