diff --git a/bytes-ext/Cargo.toml b/bytes-ext/Cargo.toml
deleted file mode 100644
index de70045de6..0000000000
--- a/bytes-ext/Cargo.toml
+++ /dev/null
@@ -1,8 +0,0 @@
-[package]
-name = "bytes-ext"
-version = "0.1.0"
-edition = "2018"
-
-[dependencies]
-error-chain = "0.11"
-bytes = "0.4"
diff --git a/bytes-ext/src/lib.rs b/bytes-ext/src/lib.rs
deleted file mode 100644
index 8008c5a1e9..0000000000
--- a/bytes-ext/src/lib.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-/*
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This software may be used and distributed according to the terms of the
- * GNU General Public License found in the LICENSE file in the root
- * directory of this source tree.
- */
-
-//! Extensions for the bytes crate.
-
-#![deny(warnings)]
-
-mod sized;
-
-pub use crate::sized::SizeCounter;
diff --git a/bytes-ext/src/sized.rs b/bytes-ext/src/sized.rs
deleted file mode 100644
index 21a7a03c74..0000000000
--- a/bytes-ext/src/sized.rs
+++ /dev/null
@@ -1,126 +0,0 @@
-/*
- * Copyright (c) Facebook, Inc. and its affiliates.
- *
- * This software may be used and distributed according to the terms of the
- * GNU General Public License found in the LICENSE file in the root
- * directory of this source tree.
- */
-
-use std::usize;
-
-use bytes::{Buf, BufMut, ByteOrder, IntoBuf};
-//use iovec::IoVec;
-
-/// Implementation of `BufMut` to count the size of a resulting buffer
-///
-/// A "buffer" for counting the size of a resulting buffer. This effectively requires
-/// the data to be serialized twice, but with luck inlining will result in most effort used
-/// in generating actual data will be elided.
-pub struct SizeCounter(usize);
-
-impl SizeCounter {
-    #[inline]
-    pub fn new() -> Self {
-        SizeCounter(0)
-    }
-
-    #[inline]
-    pub fn size(&self) -> usize {
-        self.0
-    }
-
-    #[inline]
-    pub fn increment(&mut self, inc: usize) {
-        self.0 += inc;
-    }
-}
-
-impl BufMut for SizeCounter {
-    #[inline]
-    fn remaining_mut(&self) -> usize {
-        usize::MAX
-    }
-
-    unsafe fn advance_mut(&mut self, _cnt: usize) {}
-
-    unsafe fn bytes_mut(&mut self) -> &mut [u8] {
-        unimplemented!("SizeCounter doesn't really have a buffer")
-    }
-
-    #[inline]
-    fn has_remaining_mut(&self) -> bool {
-        true
-    }
-
-    //unsafe fn bytes_vec_mut<'a>(&'a mut self, _dst: &mut [&'a mut IoVec]) -> usize {
-    //    unimplemented!("SizeCounter doesn't really have a buffer")
-    //}
-
-    #[inline]
-    fn put<T: IntoBuf>(&mut self, src: T)
-    where
-        Self: Sized,
-    {
-        let buf = src.into_buf();
-        self.0 += buf.remaining();
-    }
-
-    #[inline]
-    fn put_slice(&mut self, src: &[u8]) {
-        self.0 += src.len()
-    }
-
-    #[inline]
-    fn put_u8(&mut self, _n: u8) {
-        self.0 += 1
-    }
-    #[inline]
-    fn put_i8(&mut self, _n: i8) {
-        self.0 += 1
-    }
-
-    #[inline]
-    fn put_u16<T: ByteOrder>(&mut self, _n: u16) {
-        self.0 += 2
-    }
-    #[inline]
-    fn put_i16<T: ByteOrder>(&mut self, _n: i16) {
-        self.0 += 2
-    }
-
-    #[inline]
-    fn put_u32<T: ByteOrder>(&mut self, _n: u32) {
-        self.0 += 4
-    }
-    #[inline]
-    fn put_i32<T: ByteOrder>(&mut self, _n: i32) {
-        self.0 += 4
-    }
-
-    #[inline]
-    fn put_u64<T: ByteOrder>(&mut self, _n: u64) {
-        self.0 += 8
-    }
-    #[inline]
-    fn put_i64<T: ByteOrder>(&mut self, _n: i64) {
-        self.0 += 8
-    }
-
-    #[inline]
-    fn put_uint<T: ByteOrder>(&mut self, _n: u64, nbytes: usize) {
-        self.0 += nbytes
-    }
-    #[inline]
-    fn put_int<T: ByteOrder>(&mut self, _n: i64, nbytes: usize) {
-        self.0 += nbytes
-    }
-
-    #[inline]
-    fn put_f32<T: ByteOrder>(&mut self, _n: f32) {
-        self.0 += 4
-    }
-    #[inline]
-    fn put_f64<T: ByteOrder>(&mut self, _n: f64) {
-        self.0 += 8
-    }
-}
diff --git a/mercurial/bundles/src/delta.rs b/mercurial/bundles/src/delta.rs
index 66989f4425..0e3a7add9d 100644
--- a/mercurial/bundles/src/delta.rs
+++ b/mercurial/bundles/src/delta.rs
@@ -10,7 +10,7 @@
 
 use bytes::{BufMut, BytesMut};
 
-use bytes_ext::SizeCounter;
+use bufsize::SizeCounter;
 use failure_ext::bail_err;
 use mercurial_types::delta::{Delta, Fragment};