diff --git a/src/error.rs b/src/error.rs
index f9c5824..41ffff7 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -17,7 +17,7 @@ where
 
     /// Attempted to issue a `call` when no more requests can be in flight.
     ///
-    /// See [`tower_service::Service::poll_ready`] and [`Client::with_limit`].
+    /// See [`tower_service::Service::poll_ready`].
     TransportFull,
 
     /// Attempted to issue a `call`, but the underlying transport has been closed.
diff --git a/src/lib.rs b/src/lib.rs
index 0b38dd0..0228876 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -140,6 +140,7 @@
     rust_2018_idioms
 )]
 #![allow(clippy::type_complexity)]
+#![feature(type_alias_impl_trait)]
 
 const YIELD_EVERY: usize = 24;
 
@@ -231,3 +232,20 @@ mod sealed {
 
 pub mod multiplex;
 pub mod pipeline;
+
+/// impl Future.
+///
+/// https://github.com/rust-lang/rust/issues/65863
+#[cfg(doc)]
+pub struct DocFuture<O>(std::marker::PhantomData<O>);
+
+#[cfg(doc)]
+impl<O> std::future::Future for DocFuture<O> {
+    type Output = O;
+    fn poll(
+        self: std::pin::Pin<&mut Self>,
+        _: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Self::Output> {
+        unreachable!()
+    }
+}
diff --git a/src/multiplex/client.rs b/src/multiplex/client.rs
index 045fb9c..e6043c7 100644
--- a/src/multiplex/client.rs
+++ b/src/multiplex/client.rs
@@ -93,11 +93,15 @@ where
 {
     type Error = SpawnError<NT::MakeError>;
     type Response = Client<NT::Transport, Error<NT::Transport, Request>, Request>;
-    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
+
+    #[cfg(not(doc))]
+    type Future = impl Future<Output = Result<Self::Response, Self::Error>> + Send;
+    #[cfg(doc)]
+    type Future = crate::DocFuture<Result<Self::Response, Self::Error>>;
 
     fn call(&mut self, target: Target) -> Self::Future {
         let maker = self.t_maker.make_transport(target);
-        Box::pin(async move { Ok(Client::new(maker.await.map_err(SpawnError::Inner)?)) })
+        async move { Ok(Client::new(maker.await.map_err(SpawnError::Inner)?)) }
     }
 
     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
@@ -390,7 +394,11 @@ where
 {
     type Response = T::Ok;
     type Error = E;
-    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
+
+    #[cfg(not(doc))]
+    type Future = impl Future<Output = Result<Self::Response, Self::Error>> + Send;
+    #[cfg(doc)]
+    type Future = crate::DocFuture<Result<Self::Response, Self::Error>>;
 
     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), E>> {
         Poll::Ready(ready!(self.mediator.poll_ready(cx)).map_err(|_| E::from(Error::ClientDropped)))
@@ -402,7 +410,7 @@ where
         tracing::trace!("issuing request");
         let req = ClientRequest { req, span, res: tx };
         let r = self.mediator.try_send(req);
-        Box::pin(async move {
+        async move {
             match r {
                 Ok(()) => match rx.await {
                     Ok(r) => {
@@ -413,7 +421,7 @@ where
                 },
                 Err(_) => Err(E::from(Error::TransportFull)),
             }
-        })
+        }
     }
 }
 
diff --git a/src/multiplex/mod.rs b/src/multiplex/mod.rs
index f63cb1b..4aa780b 100644
--- a/src/multiplex/mod.rs
+++ b/src/multiplex/mod.rs
@@ -26,7 +26,7 @@ pub mod server;
 pub use self::server::Server;
 
 /// A convenience wrapper that lets you take separate transport and tag store types and use them as
-/// a single [`client::Transport`].
+/// a single transport.
 #[pin_project]
 #[derive(Debug)]
 pub struct MultiplexTransport<T, S> {
diff --git a/src/pipeline/client.rs b/src/pipeline/client.rs
index fd61f87..f3b8544 100644
--- a/src/pipeline/client.rs
+++ b/src/pipeline/client.rs
@@ -72,11 +72,15 @@ where
 {
     type Error = SpawnError<NT::MakeError>;
     type Response = Client<NT::Transport, Error<NT::Transport, Request>, Request>;
-    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
+
+    #[cfg(not(doc))]
+    type Future = impl Future<Output = Result<Self::Response, Self::Error>> + Send;
+    #[cfg(doc)]
+    type Future = crate::DocFuture<Result<Self::Response, Self::Error>>;
 
     fn call(&mut self, target: Target) -> Self::Future {
         let maker = self.t_maker.make_transport(target);
-        Box::pin(async move { Ok(Client::new(maker.await.map_err(SpawnError::Inner)?)) })
+        async move { Ok(Client::new(maker.await.map_err(SpawnError::Inner)?)) }
     }
 
     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
@@ -350,7 +354,11 @@ where
 {
     type Response = T::Ok;
     type Error = E;
-    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
+
+    #[cfg(not(doc))]
+    type Future = impl Future<Output = Result<Self::Response, Self::Error>> + Send;
+    #[cfg(doc)]
+    type Future = crate::DocFuture<Result<Self::Response, Self::Error>>;
 
     fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), E>> {
         Poll::Ready(ready!(self.mediator.poll_ready(cx)).map_err(|_| E::from(Error::ClientDropped)))
@@ -362,7 +370,7 @@ where
         tracing::trace!("issuing request");
         let req = ClientRequest { req, span, res: tx };
         let r = self.mediator.try_send(req);
-        Box::pin(async move {
+        async move {
             match r {
                 Ok(()) => match rx.await {
                     Ok(r) => {
@@ -373,7 +381,7 @@ where
                 },
                 Err(_) => Err(E::from(Error::TransportFull)),
             }
-        })
+        }
     }
 }