diff --git a/tokio-buf/Cargo.toml b/tokio-buf/Cargo.toml
index 2eb938a50..83a904854 100644
--- a/tokio-buf/Cargo.toml
+++ b/tokio-buf/Cargo.toml
@@ -22,5 +22,5 @@ either = { version =  "1.5", optional = true}
 futures = "0.1.23"
 
 [features]
-default = ["ext"]
-ext = ["bytes/either", "either"]
+default = ["util"]
+util = ["bytes/either", "either"]
diff --git a/tokio-buf/src/errors.rs b/tokio-buf/src/errors.rs
deleted file mode 100644
index d87f1f8c2..000000000
--- a/tokio-buf/src/errors.rs
+++ /dev/null
@@ -1,35 +0,0 @@
-//! Error types
-
-#[cfg(feature = "ext")]
-pub use ext::CollectError;
-#[cfg(feature = "ext")]
-pub use ext::CollectVecError;
-#[cfg(feature = "ext")]
-pub use ext::LimitError;
-
-// Being crate-private, we should be able to swap the type out in a
-// backwards compatible way.
-pub(crate) mod internal {
-    use std::{error, fmt};
-
-    /// An error that can never occur
-    pub enum Never {}
-
-    impl fmt::Debug for Never {
-        fn fmt(&self, _f: &mut fmt::Formatter) -> fmt::Result {
-            match *self {}
-        }
-    }
-
-    impl fmt::Display for Never {
-        fn fmt(&self, _f: &mut fmt::Formatter) -> fmt::Result {
-            match *self {}
-        }
-    }
-
-    impl error::Error for Never {
-        fn description(&self) -> &str {
-            match *self {}
-        }
-    }
-}
diff --git a/tokio-buf/src/lib.rs b/tokio-buf/src/lib.rs
index b5da17b1f..0c4d7bd83 100644
--- a/tokio-buf/src/lib.rs
+++ b/tokio-buf/src/lib.rs
@@ -1,5 +1,5 @@
 #![doc(html_root_url = "https://docs.rs/tokio-buf/0.1.0")]
-#![deny(missing_docs, missing_debug_implementations)]
+#![deny(missing_docs, missing_debug_implementations, unreachable_pub)]
 #![cfg_attr(test, deny(warnings))]
 
 //! Asynchronous stream of bytes.
@@ -10,27 +10,26 @@
 //! `Buf` (i.e, byte collections).
 
 extern crate bytes;
-#[cfg(feature = "ext")]
+#[cfg(feature = "util")]
 extern crate either;
 #[allow(unused)]
 #[macro_use]
 extern crate futures;
 
-pub mod errors;
-#[cfg(feature = "ext")]
-pub mod ext;
+mod never;
+#[cfg(feature = "util")]
+pub mod util;
 mod size_hint;
 mod str;
+mod u8;
 
 pub use self::size_hint::SizeHint;
 #[doc(inline)]
-#[cfg(feature = "ext")]
-pub use ext::BufStreamExt;
+#[cfg(feature = "util")]
+pub use util::BufStreamExt;
 
-use bytes::{Buf, Bytes, BytesMut};
-use errors::internal::Never;
+use bytes::Buf;
 use futures::Poll;
-use std::io;
 
 /// An asynchronous stream of bytes.
 ///
@@ -98,64 +97,3 @@ pub trait BufStream {
         SizeHint::default()
     }
 }
-
-impl BufStream for Vec<u8> {
-    type Item = io::Cursor<Vec<u8>>;
-    type Error = Never;
-
-    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
-        if self.is_empty() {
-            return Ok(None.into());
-        }
-
-        poll_bytes(self)
-    }
-}
-
-impl BufStream for &'static [u8] {
-    type Item = io::Cursor<&'static [u8]>;
-    type Error = Never;
-
-    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
-        if self.is_empty() {
-            return Ok(None.into());
-        }
-
-        poll_bytes(self)
-    }
-}
-
-impl BufStream for Bytes {
-    type Item = io::Cursor<Bytes>;
-    type Error = Never;
-
-    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
-        if self.is_empty() {
-            return Ok(None.into());
-        }
-
-        poll_bytes(self)
-    }
-}
-
-impl BufStream for BytesMut {
-    type Item = io::Cursor<BytesMut>;
-    type Error = Never;
-
-    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
-        if self.is_empty() {
-            return Ok(None.into());
-        }
-
-        poll_bytes(self)
-    }
-}
-
-fn poll_bytes<T: Default>(buf: &mut T) -> Poll<Option<io::Cursor<T>>, Never> {
-    use std::mem;
-
-    let bytes = mem::replace(buf, Default::default());
-    let buf = io::Cursor::new(bytes);
-
-    Ok(Some(buf).into())
-}
diff --git a/tokio-buf/src/never.rs b/tokio-buf/src/never.rs
new file mode 100644
index 000000000..dcbde39c5
--- /dev/null
+++ b/tokio-buf/src/never.rs
@@ -0,0 +1,22 @@
+use std::{error, fmt};
+
+/// An error that can never occur
+pub enum Never {}
+
+impl fmt::Debug for Never {
+    fn fmt(&self, _f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {}
+    }
+}
+
+impl fmt::Display for Never {
+    fn fmt(&self, _f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {}
+    }
+}
+
+impl error::Error for Never {
+    fn description(&self) -> &str {
+        match *self {}
+    }
+}
diff --git a/tokio-buf/src/str.rs b/tokio-buf/src/str.rs
index 4b73ad005..b8a6eb643 100644
--- a/tokio-buf/src/str.rs
+++ b/tokio-buf/src/str.rs
@@ -1,4 +1,4 @@
-use errors::internal::Never;
+use never::Never;
 use BufStream;
 
 use futures::Poll;
diff --git a/tokio-buf/src/u8.rs b/tokio-buf/src/u8.rs
new file mode 100644
index 000000000..dece1d7c9
--- /dev/null
+++ b/tokio-buf/src/u8.rs
@@ -0,0 +1,66 @@
+use BufStream;
+use never::Never;
+use bytes::{Bytes, BytesMut};
+use futures::Poll;
+use std::io;
+
+impl BufStream for Vec<u8> {
+    type Item = io::Cursor<Vec<u8>>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        poll_bytes(self)
+    }
+}
+
+impl BufStream for &'static [u8] {
+    type Item = io::Cursor<&'static [u8]>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        poll_bytes(self)
+    }
+}
+
+impl BufStream for Bytes {
+    type Item = io::Cursor<Bytes>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        poll_bytes(self)
+    }
+}
+
+impl BufStream for BytesMut {
+    type Item = io::Cursor<BytesMut>;
+    type Error = Never;
+
+    fn poll_buf(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
+        if self.is_empty() {
+            return Ok(None.into());
+        }
+
+        poll_bytes(self)
+    }
+}
+
+fn poll_bytes<T: Default>(buf: &mut T) -> Poll<Option<io::Cursor<T>>, Never> {
+    use std::mem;
+
+    let bytes = mem::replace(buf, Default::default());
+    let buf = io::Cursor::new(bytes);
+
+    Ok(Some(buf).into())
+}
diff --git a/tokio-buf/src/ext/chain.rs b/tokio-buf/src/util/chain.rs
similarity index 100%
rename from tokio-buf/src/ext/chain.rs
rename to tokio-buf/src/util/chain.rs
diff --git a/tokio-buf/src/ext/collect.rs b/tokio-buf/src/util/collect.rs
similarity index 100%
rename from tokio-buf/src/ext/collect.rs
rename to tokio-buf/src/util/collect.rs
diff --git a/tokio-buf/src/ext/from.rs b/tokio-buf/src/util/from.rs
similarity index 100%
rename from tokio-buf/src/ext/from.rs
rename to tokio-buf/src/util/from.rs
diff --git a/tokio-buf/src/ext/limit.rs b/tokio-buf/src/util/limit.rs
similarity index 100%
rename from tokio-buf/src/ext/limit.rs
rename to tokio-buf/src/util/limit.rs
diff --git a/tokio-buf/src/ext/mod.rs b/tokio-buf/src/util/mod.rs
similarity index 92%
rename from tokio-buf/src/ext/mod.rs
rename to tokio-buf/src/util/mod.rs
index f0299129c..2a3dfbf7f 100644
--- a/tokio-buf/src/ext/mod.rs
+++ b/tokio-buf/src/util/mod.rs
@@ -10,9 +10,13 @@ pub use self::collect::Collect;
 pub use self::from::FromBufStream;
 pub use self::limit::Limit;
 
-pub use self::collect::CollectError;
-pub use self::from::CollectVecError;
-pub use self::limit::LimitError;
+pub mod error {
+    //! Error types
+
+    pub use super::collect::CollectError;
+    pub use super::from::CollectVecError;
+    pub use super::limit::LimitError;
+}
 
 use BufStream;