diff --git a/tower-timeout/src/error.rs b/tower-timeout/src/error.rs
new file mode 100644
index 0000000..6853297
--- /dev/null
+++ b/tower-timeout/src/error.rs
@@ -0,0 +1,17 @@
+//! Error types
+
+use std::{error, fmt};
+
+pub(crate) type Error = Box<error::Error + Send + Sync>;
+
+/// The timeout elapsed.
+#[derive(Debug)]
+pub struct Elapsed(pub(super) ());
+
+impl fmt::Display for Elapsed {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.pad("request timed out")
+    }
+}
+
+impl error::Error for Elapsed {}
diff --git a/tower-timeout/src/future.rs b/tower-timeout/src/future.rs
new file mode 100644
index 0000000..712e12e
--- /dev/null
+++ b/tower-timeout/src/future.rs
@@ -0,0 +1,41 @@
+//! Future types
+
+use crate::error::{Elapsed, Error};
+use futures::{Async, Future, Poll};
+use tokio_timer::Delay;
+
+/// `Timeout` response future
+#[derive(Debug)]
+pub struct ResponseFuture<T> {
+    response: T,
+    sleep: Delay,
+}
+
+impl<T> ResponseFuture<T> {
+    pub(crate) fn new(response: T, sleep: Delay) -> Self {
+        ResponseFuture { response, sleep }
+    }
+}
+
+impl<T> Future for ResponseFuture<T>
+where
+    T: Future,
+    Error: From<T::Error>,
+{
+    type Item = T::Item;
+    type Error = Error;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        // First, try polling the future
+        match self.response.poll()? {
+            Async::Ready(v) => return Ok(Async::Ready(v)),
+            Async::NotReady => {}
+        }
+
+        // Now check the sleep
+        match self.sleep.poll()? {
+            Async::NotReady => Ok(Async::NotReady),
+            Async::Ready(_) => Err(Elapsed(()).into()),
+        }
+    }
+}
diff --git a/tower-timeout/src/layer.rs b/tower-timeout/src/layer.rs
new file mode 100644
index 0000000..4ac3c1d
--- /dev/null
+++ b/tower-timeout/src/layer.rs
@@ -0,0 +1,32 @@
+use crate::{Error, Timeout};
+use std::time::Duration;
+use tower_layer::Layer;
+use tower_service::Service;
+
+/// Applies a timeout to requests via the supplied inner service.
+#[derive(Debug)]
+pub struct TimeoutLayer {
+    timeout: Duration,
+}
+
+impl TimeoutLayer {
+    /// Create a timeout from a duration
+    pub fn new(timeout: Duration) -> Self {
+        TimeoutLayer { timeout }
+    }
+}
+
+impl<S, Request> Layer<S, Request> for TimeoutLayer
+where
+    S: Service<Request>,
+    Error: From<S::Error>,
+{
+    type Response = S::Response;
+    type Error = Error;
+    type LayerError = ();
+    type Service = Timeout<S>;
+
+    fn layer(&self, service: S) -> Result<Self::Service, Self::LayerError> {
+        Ok(Timeout::new(service, self.timeout))
+    }
+}
diff --git a/tower-timeout/src/lib.rs b/tower-timeout/src/lib.rs
index 7df3aa8..7ea883c 100644
--- a/tower-timeout/src/lib.rs
+++ b/tower-timeout/src/lib.rs
@@ -12,17 +12,21 @@ extern crate tokio_timer;
 extern crate tower_layer;
 extern crate tower_service;
 
-use futures::{Async, Future, Poll};
+pub mod error;
+pub mod future;
+mod layer;
+
+pub use crate::layer::TimeoutLayer;
+
+use crate::error::Error;
+use crate::future::ResponseFuture;
+use futures::Poll;
 use tokio_timer::{clock, Delay};
-use tower_layer::Layer;
+
 use tower_service::Service;
 
 use std::time::Duration;
 
-use self::error::Elapsed;
-
-type Error = Box<::std::error::Error + Send + Sync>;
-
 /// Applies a timeout to requests.
 #[derive(Debug, Clone)]
 pub struct Timeout<T> {
@@ -30,43 +34,6 @@ pub struct Timeout<T> {
     timeout: Duration,
 }
 
-/// Applies a timeout to requests via the supplied inner service.
-#[derive(Debug)]
-pub struct TimeoutLayer {
-    timeout: Duration,
-}
-
-/// `Timeout` response future
-#[derive(Debug)]
-pub struct ResponseFuture<T> {
-    response: T,
-    sleep: Delay,
-}
-
-// ===== impl TimeoutLayer =====
-
-impl TimeoutLayer {
-    /// Create a timeout from a duration
-    pub fn new(timeout: Duration) -> Self {
-        TimeoutLayer { timeout }
-    }
-}
-
-impl<S, Request> Layer<S, Request> for TimeoutLayer
-where
-    S: Service<Request>,
-    S::Error: Into<Error>,
-{
-    type Response = S::Response;
-    type Error = Error;
-    type LayerError = ();
-    type Service = Timeout<S>;
-
-    fn layer(&self, service: S) -> Result<Self::Service, Self::LayerError> {
-        Ok(Timeout::new(service, self.timeout))
-    }
-}
-
 // ===== impl Timeout =====
 
 impl<T> Timeout<T> {
@@ -79,7 +46,7 @@ impl<T> Timeout<T> {
 impl<S, Request> Service<Request> for Timeout<S>
 where
     S: Service<Request>,
-    S::Error: Into<Error>,
+    Error: From<S::Error>,
 {
     type Response = S::Response;
     type Error = Error;
@@ -90,53 +57,9 @@ where
     }
 
     fn call(&mut self, request: Request) -> Self::Future {
-        ResponseFuture {
-            response: self.inner.call(request),
-            sleep: Delay::new(clock::now() + self.timeout),
-        }
+        let response = self.inner.call(request);
+        let sleep = Delay::new(clock::now() + self.timeout);
+
+        ResponseFuture::new(response, sleep)
     }
 }
-
-// ===== impl ResponseFuture =====
-
-impl<T> Future for ResponseFuture<T>
-where
-    T: Future,
-    T::Error: Into<Error>,
-{
-    type Item = T::Item;
-    type Error = Error;
-
-    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-        // First, try polling the future
-        match self.response.poll().map_err(Into::into)? {
-            Async::Ready(v) => return Ok(Async::Ready(v)),
-            Async::NotReady => {}
-        }
-
-        // Now check the sleep
-        match self.sleep.poll()? {
-            Async::NotReady => Ok(Async::NotReady),
-            Async::Ready(_) => Err(Elapsed(()).into()),
-        }
-    }
-}
-
-// ===== impl Error =====
-
-/// Timeout error types
-pub mod error {
-    use std::{error::Error, fmt};
-
-    /// The timeout elapsed.
-    #[derive(Debug)]
-    pub struct Elapsed(pub(super) ());
-
-    impl fmt::Display for Elapsed {
-        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-            f.pad("request timed out")
-        }
-    }
-
-    impl Error for Elapsed {}
-}