diff --git a/examples/client.rs b/examples/client.rs
index f5587ef330..00ae1c26bb 100644
--- a/examples/client.rs
+++ b/examples/client.rs
@@ -1,7 +1,5 @@
 #![deny(warnings)]
-extern crate hyper;
-extern crate pretty_env_logger;
-
+#![warn(rust_2018_idioms)]
 use std::env;
 use std::io::{self, Write};
 
diff --git a/examples/client_json.rs b/examples/client_json.rs
index 1188a76e90..4239ba9a36 100644
--- a/examples/client_json.rs
+++ b/examples/client_json.rs
@@ -1,9 +1,8 @@
 #![deny(warnings)]
-extern crate hyper;
+#![warn(rust_2018_idioms)]
+
 #[macro_use]
 extern crate serde_derive;
-extern crate serde;
-extern crate serde_json;
 
 use hyper::Client;
 use futures_util::TryStreamExt;
diff --git a/examples/multi_server.rs b/examples/multi_server.rs
index 5b2433abbc..6d38478e60 100644
--- a/examples/multi_server.rs
+++ b/examples/multi_server.rs
@@ -1,6 +1,5 @@
 #![deny(warnings)]
-extern crate hyper;
-extern crate pretty_env_logger;
+#![warn(rust_2018_idioms)]
 
 use hyper::{Body, Request, Response, Server};
 use hyper::service::{service_fn, make_service_fn};
diff --git a/examples/params.rs b/examples/params.rs
index 7f7867b893..6c2788059f 100644
--- a/examples/params.rs
+++ b/examples/params.rs
@@ -1,7 +1,5 @@
 // #![deny(warnings)]  // FIXME: https://github.com/rust-lang/rust/issues/62411
-extern crate hyper;
-extern crate pretty_env_logger;
-extern crate url;
+#![warn(rust_2018_idioms)]
 
 use hyper::{Body, Method, Request, Response, Server, StatusCode};
 use hyper::service::{service_fn, make_service_fn};
diff --git a/src/body/body.rs b/src/body/body.rs
index 020de397f0..d147cf6946 100644
--- a/src/body/body.rs
+++ b/src/body/body.rs
@@ -7,7 +7,6 @@ use futures_core::{Stream, TryStream};
 use futures_channel::{mpsc, oneshot};
 use futures_util::TryStreamExt;
 //use tokio_buf::SizeHint;
-use h2;
 use http::HeaderMap;
 
 use crate::common::{Future, Never, Pin, Poll, task};
@@ -130,7 +129,6 @@ impl Body {
     ///
     /// ```
     /// # use hyper::Body;
-    /// # use futures_util;
     /// # fn main() {
     /// let chunks: Vec<Result<_, ::std::io::Error>> = vec![
     ///     Ok("hello"),
@@ -346,7 +344,7 @@ impl Payload for Body {
 }
 
 impl fmt::Debug for Body {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         #[derive(Debug)]
         struct Streaming;
         #[derive(Debug)]
diff --git a/src/body/chunk.rs b/src/body/chunk.rs
index c8c469892a..f3524cf425 100644
--- a/src/body/chunk.rs
+++ b/src/body/chunk.rs
@@ -113,7 +113,7 @@ impl AsRef<[u8]> for Chunk {
 
 impl fmt::Debug for Chunk {
     #[inline]
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(&self.bytes, f)
     }
 }
diff --git a/src/client/conn.rs b/src/client/conn.rs
index 8e743e0a4a..795642fd8e 100644
--- a/src/client/conn.rs
+++ b/src/client/conn.rs
@@ -14,7 +14,6 @@ use std::sync::Arc;
 
 use bytes::Bytes;
 use futures_util::future::{self, Either, FutureExt as _};
-use h2;
 use tokio_io::{AsyncRead, AsyncWrite};
 
 use crate::body::Payload;
@@ -258,7 +257,7 @@ impl<T, B> Service for SendRequest<T, B> {
 */
 
 impl<B> fmt::Debug for SendRequest<B> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("SendRequest")
             .finish()
     }
@@ -305,7 +304,7 @@ where
 }
 
 impl<B> fmt::Debug for Http2SendRequest<B> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Http2SendRequest")
             .finish()
     }
@@ -410,7 +409,7 @@ where
     T: AsyncRead + AsyncWrite + fmt::Debug + Send + 'static,
     B: Payload + 'static,
 {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Connection")
             .finish()
     }
@@ -575,7 +574,7 @@ impl Future for ResponseFuture {
 }
 
 impl fmt::Debug for ResponseFuture {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("ResponseFuture")
             .finish()
     }
diff --git a/src/client/connect/dns.rs b/src/client/connect/dns.rs
index d31756eefb..6237dd5a48 100644
--- a/src/client/connect/dns.rs
+++ b/src/client/connect/dns.rs
@@ -75,13 +75,13 @@ impl Name {
 }
 
 impl fmt::Debug for Name {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(&self.host, f)
     }
 }
 
 impl fmt::Display for Name {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(&self.host, f)
     }
 }
@@ -100,7 +100,7 @@ impl FromStr for Name {
 pub struct InvalidNameError(());
 
 impl fmt::Display for InvalidNameError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str("Not a valid domain name")
     }
 }
@@ -166,7 +166,7 @@ impl Resolve for GaiResolver {
 }
 
 impl fmt::Debug for GaiResolver {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.pad("GaiResolver")
     }
 }
@@ -184,7 +184,7 @@ impl Future for GaiFuture {
 }
 
 impl fmt::Debug for GaiFuture {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.pad("GaiFuture")
     }
 }
@@ -198,7 +198,7 @@ impl Iterator for GaiAddrs {
 }
 
 impl fmt::Debug for GaiAddrs {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.pad("GaiAddrs")
     }
 }
diff --git a/src/client/connect/http.rs b/src/client/connect/http.rs
index e8fc792ae9..b39d0261a0 100644
--- a/src/client/connect/http.rs
+++ b/src/client/connect/http.rs
@@ -198,7 +198,7 @@ impl<R> HttpConnector<R> {
 
 // R: Debug required for now to allow adding it to debug output later...
 impl<R: fmt::Debug> fmt::Debug for HttpConnector<R> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("HttpConnector")
             .finish()
     }
@@ -282,7 +282,7 @@ enum InvalidUrl {
 }
 
 impl fmt::Display for InvalidUrl {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str(self.description())
     }
 }
@@ -382,7 +382,7 @@ where
 }
 
 impl<R: Resolve + fmt::Debug> fmt::Debug for HttpConnecting<R> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.pad("HttpConnecting")
     }
 }
@@ -615,8 +615,6 @@ mod tests {
     #[test]
     #[cfg_attr(not(feature = "__internal_happy_eyeballs_tests"), ignore)]
     fn client_happy_eyeballs() {
-        extern crate pretty_env_logger;
-
         use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, TcpListener};
         use std::time::{Duration, Instant};
 
diff --git a/src/client/connect/mod.rs b/src/client/connect/mod.rs
index d26b0628b4..0134ef9551 100644
--- a/src/client/connect/mod.rs
+++ b/src/client/connect/mod.rs
@@ -346,7 +346,7 @@ impl Clone for Extra {
 }
 
 impl fmt::Debug for Extra {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Extra")
             .finish()
     }
diff --git a/src/client/dispatch.rs b/src/client/dispatch.rs
index c30e03856f..b003e9da6b 100644
--- a/src/client/dispatch.rs
+++ b/src/client/dispatch.rs
@@ -1,7 +1,6 @@
 use futures_core::Stream;
 use futures_channel::{mpsc, oneshot};
 use futures_util::future;
-use want;
 
 use crate::common::{Future, Never, Pin, Poll, task};
 
@@ -254,7 +253,6 @@ mod tests {
     // trigger a warning to remind us
     use crate::Error;
     /*
-    extern crate pretty_env_logger;
     #[cfg(feature = "nightly")]
     extern crate test;
 
diff --git a/src/client/mod.rs b/src/client/mod.rs
index cdf122af08..4181b901b6 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -137,7 +137,6 @@ impl Client<(), Body> {
     /// # Example
     ///
     /// ```
-    /// # extern crate hyper;
     /// # #[cfg(feature  = "runtime")]
     /// # fn run () {
     /// use hyper::Client;
@@ -175,7 +174,6 @@ where C: Connect + Sync + 'static,
     /// # Example
     ///
     /// ```
-    /// # extern crate hyper;
     /// # #[cfg(feature  = "runtime")]
     /// # fn run () {
     /// use hyper::{Client, Uri};
@@ -205,7 +203,6 @@ where C: Connect + Sync + 'static,
     /// # Example
     ///
     /// ```
-    /// # extern crate hyper;
     /// # #[cfg(feature  = "runtime")]
     /// # fn run () {
     /// use hyper::{Body, Client, Request};
@@ -558,7 +555,7 @@ impl<C, B> Clone for Client<C, B> {
 }
 
 impl<C, B> fmt::Debug for Client<C, B> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Client")
             .finish()
     }
@@ -580,7 +577,7 @@ impl ResponseFuture {
 }
 
 impl fmt::Debug for ResponseFuture {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.pad("Future<Response>")
     }
 }
@@ -821,7 +818,6 @@ fn set_scheme(uri: &mut Uri, scheme: Scheme) {
 /// # Example
 ///
 /// ```
-/// # extern crate hyper;
 /// # #[cfg(feature  = "runtime")]
 /// # fn run () {
 /// use hyper::Client;
@@ -1053,7 +1049,7 @@ impl Builder {
 }
 
 impl fmt::Debug for Builder {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Builder")
             .field("client_config", &self.client_config)
             .field("conn_builder", &self.conn_builder)
@@ -1097,7 +1093,6 @@ mod unit_tests {
 
     #[test]
     fn test_authority_form() {
-        extern crate pretty_env_logger;
         let _ = pretty_env_logger::try_init();
 
         let mut uri = "http://hyper.rs".parse().unwrap();
diff --git a/src/client/pool.rs b/src/client/pool.rs
index 7bdd91e310..716a2c9232 100644
--- a/src/client/pool.rs
+++ b/src/client/pool.rs
@@ -171,7 +171,7 @@ impl<T: Poolable> Pool<T> {
     }
 
     #[cfg(test)]
-    fn locked(&self) -> ::std::sync::MutexGuard<PoolInner<T>> {
+    fn locked(&self) -> ::std::sync::MutexGuard<'_, PoolInner<T>> {
         self
             .inner
             .as_ref()
@@ -263,7 +263,7 @@ impl<T: Poolable> Pool<T> {
 }
 
 /// Pop off this list, looking for a usable connection that hasn't expired.
-struct IdlePopper<'a, T: 'a> {
+struct IdlePopper<'a, T> {
     key: &'a Key,
     list: &'a mut Vec<Idle<T>>,
 }
@@ -547,7 +547,7 @@ impl<T: Poolable> Drop for Pooled<T> {
 }
 
 impl<T: Poolable> fmt::Debug for Pooled<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Pooled")
             .field("key", &self.key)
             .finish()
diff --git a/src/client/tests.rs b/src/client/tests.rs
index c26256ffd2..b96c6f94a9 100644
--- a/src/client/tests.rs
+++ b/src/client/tests.rs
@@ -3,7 +3,6 @@
 use super::Client;
 /*
 #![cfg(feature = "runtime")]
-extern crate pretty_env_logger;
 
 use futures::{Async, Future, Stream};
 use futures::future::poll_fn;
diff --git a/src/common/exec.rs b/src/common/exec.rs
index baf3650521..1650c8f7c5 100644
--- a/src/common/exec.rs
+++ b/src/common/exec.rs
@@ -57,13 +57,13 @@ impl Exec {
                     struct TokioSpawnError;
 
                     impl fmt::Debug for TokioSpawnError {
-                        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
                             fmt::Debug::fmt("tokio::spawn failed (is a tokio runtime running this future?)", f)
                         }
                     }
 
                     impl fmt::Display for TokioSpawnError {
-                        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
                             fmt::Display::fmt("tokio::spawn failed (is a tokio runtime running this future?)", f)
                         }
                     }
@@ -99,7 +99,7 @@ impl Exec {
 }
 
 impl fmt::Debug for Exec {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Exec")
             .finish()
     }
diff --git a/src/common/io/rewind.rs b/src/common/io/rewind.rs
index b1cb68cd4f..9510f5d718 100644
--- a/src/common/io/rewind.rs
+++ b/src/common/io/rewind.rs
@@ -129,8 +129,7 @@ mod tests {
     use super::Rewind;
     /*
     use super::*;
-    extern crate tokio_mockstream;
-    use self::tokio_mockstream::MockStream;
+    use tokio_mockstream::MockStream;
     use std::io::Cursor;
 
     // Test a partial rewind
diff --git a/src/common/never.rs b/src/common/never.rs
index dfb763b2a4..c44c9adb97 100644
--- a/src/common/never.rs
+++ b/src/common/never.rs
@@ -9,7 +9,7 @@ use std::fmt;
 pub enum Never {}
 
 impl fmt::Display for Never {
-    fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {}
     }
 }
diff --git a/src/common/task.rs b/src/common/task.rs
index 9a7c2aea5b..aca869e6ef 100644
--- a/src/common/task.rs
+++ b/src/common/task.rs
@@ -4,7 +4,7 @@ use super::Never;
 /// A function to help "yield" a future, such that it is re-scheduled immediately.
 ///
 /// Useful for spin counts, so a future doesn't hog too much time.
-pub(crate) fn yield_now(cx: &mut Context) -> Poll<Never> {
+pub(crate) fn yield_now(cx: &mut Context<'_>) -> Poll<Never> {
     cx.waker().wake_by_ref();
     Poll::Pending
 }
diff --git a/src/error.rs b/src/error.rs
index 1a025c5e6f..ac01d8c421 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -3,10 +3,6 @@ use std::error::Error as StdError;
 use std::fmt;
 use std::io;
 
-use httparse;
-use http;
-use h2;
-
 /// Result type often returned from methods that can have hyper `Error`s.
 pub type Result<T> = ::std::result::Result<T, Error>;
 
@@ -284,7 +280,7 @@ impl Error {
 }
 
 impl fmt::Debug for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut f = f.debug_tuple("Error");
         f.field(&self.inner.kind);
         if let Some(ref cause) = self.inner.cause {
@@ -295,7 +291,7 @@ impl fmt::Debug for Error {
 }
 
 impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         if let Some(ref cause) = self.inner.cause {
             write!(f, "{}: {}", self.description(), cause)
         } else {
diff --git a/src/headers.rs b/src/headers.rs
index 52fcaba89b..fbacd08beb 100644
--- a/src/headers.rs
+++ b/src/headers.rs
@@ -33,7 +33,7 @@ pub fn content_length_parse_all(headers: &HeaderMap) -> Option<u64> {
     content_length_parse_all_values(headers.get_all(CONTENT_LENGTH).into_iter())
 }
 
-pub fn content_length_parse_all_values(values: ValueIter<HeaderValue>) -> Option<u64> {
+pub fn content_length_parse_all_values(values: ValueIter<'_, HeaderValue>) -> Option<u64> {
     // If multiple Content-Length headers were sent, everything can still
     // be alright if they all contain the same value, and all parse
     // correctly. If not, then it's an error.
@@ -74,7 +74,7 @@ pub fn transfer_encoding_is_chunked(headers: &HeaderMap) -> bool {
     is_chunked(headers.get_all(TRANSFER_ENCODING).into_iter())
 }
 
-pub fn is_chunked(mut encodings: ValueIter<HeaderValue>) -> bool {
+pub fn is_chunked(mut encodings: ValueIter<'_, HeaderValue>) -> bool {
     // chunked must always be the last encoding, according to spec
     if let Some(line) = encodings.next_back() {
         return is_chunked_(line);
@@ -94,7 +94,7 @@ pub fn is_chunked_(value: &HeaderValue) -> bool {
     false
 }
 
-pub fn add_chunked(mut entry: OccupiedEntry<HeaderValue>) {
+pub fn add_chunked(mut entry: OccupiedEntry<'_, HeaderValue>) {
     const CHUNKED: &'static str = "chunked";
 
     if let Some(line) = entry.iter_mut().next_back() {
diff --git a/src/lib.rs b/src/lib.rs
index 6ec2c7719b..0a6ac08b4d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,7 @@
 #![doc(html_root_url = "https://docs.rs/hyper/0.12.32")]
 #![deny(missing_docs)]
 #![deny(missing_debug_implementations)]
+#![deny(rust_2018_idioms)]
 // XXX NOOOOOOOO
 //#![cfg_attr(test, deny(warnings))]
 #![allow(warnings)]
@@ -19,7 +20,7 @@
 //! If looking for just a convenient HTTP client, consider the
 //! [reqwest](https://crates.io/crates/reqwest) crate.
 
-#[doc(hidden)] pub extern crate http;
+#[doc(hidden)] pub use http;
 #[macro_use] extern crate log;
 
 #[cfg(all(test, feature = "nightly"))]
diff --git a/src/proto/h1/conn.rs b/src/proto/h1/conn.rs
index 49fd4f368c..4ace672668 100644
--- a/src/proto/h1/conn.rs
+++ b/src/proto/h1/conn.rs
@@ -646,7 +646,7 @@ where I: AsyncRead + AsyncWrite + Unpin,
 }
 
 impl<I, B: Buf, T> fmt::Debug for Conn<I, B, T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Conn")
             .field("state", &self.state)
             .field("io", &self.io)
@@ -701,7 +701,7 @@ enum Writing {
 }
 
 impl fmt::Debug for State {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut builder = f.debug_struct("State");
         builder
             .field("reading", &self.reading)
@@ -720,7 +720,7 @@ impl fmt::Debug for State {
 }
 
 impl fmt::Debug for Writing {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
             Writing::Init => f.write_str("Init"),
             Writing::Body(ref enc) => f.debug_tuple("Body")
@@ -1112,7 +1112,6 @@ mod tests {
 
     #[test]
     fn test_conn_body_write_length() {
-        extern crate pretty_env_logger;
         let _ = pretty_env_logger::try_init();
         let _: Result<(), ()> = future::lazy(|| {
             let io = AsyncIo::new_buf(vec![], 0);
diff --git a/src/proto/h1/decode.rs b/src/proto/h1/decode.rs
index 6583ddf39b..3c1247e297 100644
--- a/src/proto/h1/decode.rs
+++ b/src/proto/h1/decode.rs
@@ -147,7 +147,7 @@ impl Decoder {
 
 
 impl fmt::Debug for Decoder {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Debug::fmt(&self.kind, f)
     }
 }
@@ -306,7 +306,7 @@ impl ChunkedState {
 struct IncompleteBody;
 
 impl fmt::Display for IncompleteBody {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str(self.description())
     }
 }
diff --git a/src/proto/h1/dispatch.rs b/src/proto/h1/dispatch.rs
index db08e4958e..bd8e048dff 100644
--- a/src/proto/h1/dispatch.rs
+++ b/src/proto/h1/dispatch.rs
@@ -602,8 +602,6 @@ mod tests {
     // trigger a warning to remind us
     use crate::Error;
     /*
-    extern crate pretty_env_logger;
-
     use super::*;
     use crate::mock::AsyncIo;
     use crate::proto::h1::ClientTransaction;
diff --git a/src/proto/h1/encode.rs b/src/proto/h1/encode.rs
index 56ed2eecea..48c27da071 100644
--- a/src/proto/h1/encode.rs
+++ b/src/proto/h1/encode.rs
@@ -298,7 +298,7 @@ impl Buf for ChunkSize {
 }
 
 impl fmt::Debug for ChunkSize {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("ChunkSize")
             .field("bytes", &&self.bytes[..self.len.into()])
             .field("pos", &self.pos)
diff --git a/src/proto/h1/io.rs b/src/proto/h1/io.rs
index 79e1b0ee8c..b5352f79ad 100644
--- a/src/proto/h1/io.rs
+++ b/src/proto/h1/io.rs
@@ -42,7 +42,7 @@ impl<T, B> fmt::Debug for Buffered<T, B>
 where
     B: Buf,
 {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Buffered")
             .field("read_buf", &self.read_buf)
             .field("write_buf", &self.write_buf)
@@ -135,7 +135,7 @@ where
         }
     }
 
-    pub(super) fn parse<S>(&mut self, cx: &mut task::Context<'_>, parse_ctx: ParseContext)
+    pub(super) fn parse<S>(&mut self, cx: &mut task::Context<'_>, parse_ctx: ParseContext<'_>)
         -> Poll<crate::Result<ParsedMessage<S::Incoming>>>
     where
         S: Http1Transaction,
@@ -376,7 +376,7 @@ impl Cursor<Vec<u8>> {
 }
 
 impl<T: AsRef<[u8]>> fmt::Debug for Cursor<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Cursor")
             .field("pos", &self.pos)
             .field("len", &self.bytes.as_ref().len())
@@ -433,7 +433,7 @@ where
     }
 
     #[inline]
-    fn auto(&mut self) -> WriteBufAuto<B> {
+    fn auto(&mut self) -> WriteBufAuto<'_, B> {
         WriteBufAuto::new(self)
     }
 
@@ -481,7 +481,7 @@ where
 }
 
 impl<B: Buf> fmt::Debug for WriteBuf<B> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("WriteBuf")
             .field("remaining", &self.remaining())
             .field("strategy", &self.strategy)
@@ -528,7 +528,7 @@ impl<B: Buf> Buf for WriteBuf<B> {
 
 /// Detects when wrapped `WriteBuf` is used for vectored IO, and
 /// adjusts the `WriteBuf` strategy if not.
-struct WriteBufAuto<'a, B: Buf + 'a> {
+struct WriteBufAuto<'a, B: Buf> {
     bytes_called: Cell<bool>,
     bytes_vec_called: Cell<bool>,
     inner: &'a mut WriteBuf<B>,
@@ -822,7 +822,6 @@ mod tests {
     TODO: needs tokio_test::io to allow configure write_buf calls
     #[test]
     fn write_buf_queue() {
-        extern crate pretty_env_logger;
         let _ = pretty_env_logger::try_init();
 
         let mock = AsyncIo::new_buf(vec![], 1024);
@@ -844,7 +843,6 @@ mod tests {
 
     #[tokio::test]
     async fn write_buf_flatten() {
-        extern crate pretty_env_logger;
         let _ = pretty_env_logger::try_init();
 
         let mock = Mock::new()
@@ -866,7 +864,6 @@ mod tests {
 
     #[tokio::test]
     async fn write_buf_auto_flatten() {
-        extern crate pretty_env_logger;
         let _ = pretty_env_logger::try_init();
 
         let mock = Mock::new()
@@ -894,7 +891,6 @@ mod tests {
 
     #[tokio::test]
     async fn write_buf_queue_disable_auto() {
-        extern crate pretty_env_logger;
         let _ = pretty_env_logger::try_init();
 
         let mock = Mock::new()
diff --git a/src/proto/h1/mod.rs b/src/proto/h1/mod.rs
index 2784ed4fc3..65cea1391d 100644
--- a/src/proto/h1/mod.rs
+++ b/src/proto/h1/mod.rs
@@ -26,8 +26,8 @@ pub(crate) trait Http1Transaction {
     type Incoming;
     type Outgoing: Default;
     const LOG: &'static str;
-    fn parse(bytes: &mut BytesMut, ctx: ParseContext) -> ParseResult<Self::Incoming>;
-    fn encode(enc: Encode<Self::Outgoing>, dst: &mut Vec<u8>) -> crate::Result<Encoder>;
+    fn parse(bytes: &mut BytesMut, ctx: ParseContext<'_>) -> ParseResult<Self::Incoming>;
+    fn encode(enc: Encode<'_, Self::Outgoing>, dst: &mut Vec<u8>) -> crate::Result<Encoder>;
 
     fn on_error(err: &crate::Error) -> Option<MessageHead<Self::Outgoing>>;
 
@@ -68,7 +68,7 @@ pub(crate) struct ParseContext<'a> {
 }
 
 /// Passed to Http1Transaction::encode
-pub(crate) struct Encode<'a, T: 'a> {
+pub(crate) struct Encode<'a, T> {
     head: &'a mut MessageHead<T>,
     body: Option<BodyLength>,
     keep_alive: bool,
diff --git a/src/proto/h1/role.rs b/src/proto/h1/role.rs
index 9aecb8ddd9..86ad8fdb2f 100644
--- a/src/proto/h1/role.rs
+++ b/src/proto/h1/role.rs
@@ -8,7 +8,6 @@ use std::mem;
 use bytes::{BytesMut};
 use http::header::{self, Entry, HeaderName, HeaderValue};
 use http::{HeaderMap, Method, StatusCode, Version};
-use httparse;
 
 use crate::error::Parse;
 use crate::headers;
@@ -68,7 +67,7 @@ impl Http1Transaction for Server {
     type Outgoing = StatusCode;
     const LOG: &'static str = "{role=server}";
 
-    fn parse(buf: &mut BytesMut, ctx: ParseContext) -> ParseResult<RequestLine> {
+    fn parse(buf: &mut BytesMut, ctx: ParseContext<'_>) -> ParseResult<RequestLine> {
         if buf.is_empty() {
             return Ok(None);
         }
@@ -86,7 +85,7 @@ impl Http1Transaction for Server {
         // a good ~5% on pipeline benchmarks.
         let mut headers_indices: [HeaderIndices; MAX_HEADERS] = unsafe { mem::uninitialized() };
         {
-            let mut headers: [httparse::Header; MAX_HEADERS] = unsafe { mem::uninitialized() };
+            let mut headers: [httparse::Header<'_>; MAX_HEADERS] = unsafe { mem::uninitialized() };
             trace!("Request.parse([Header; {}], [u8; {}])", headers.len(), buf.len());
             let mut req = httparse::Request::new(&mut headers);
             let bytes = buf.as_ref();
@@ -239,7 +238,7 @@ impl Http1Transaction for Server {
         }))
     }
 
-    fn encode(mut msg: Encode<Self::Outgoing>, mut dst: &mut Vec<u8>) -> crate::Result<Encoder> {
+    fn encode(mut msg: Encode<'_, Self::Outgoing>, mut dst: &mut Vec<u8>) -> crate::Result<Encoder> {
         trace!(
             "Server::encode status={:?}, body={:?}, req_method={:?}",
             msg.head.subject,
@@ -589,7 +588,7 @@ impl Http1Transaction for Client {
     type Outgoing = RequestLine;
     const LOG: &'static str = "{role=client}";
 
-    fn parse(buf: &mut BytesMut, ctx: ParseContext) -> ParseResult<StatusCode> {
+    fn parse(buf: &mut BytesMut, ctx: ParseContext<'_>) -> ParseResult<StatusCode> {
         // Loop to skip information status code headers (100 Continue, etc).
         loop {
             if buf.is_empty() {
@@ -598,7 +597,7 @@ impl Http1Transaction for Client {
             // Unsafe: see comment in Server Http1Transaction, above.
             let mut headers_indices: [HeaderIndices; MAX_HEADERS] = unsafe { mem::uninitialized() };
             let (len, status, version, headers_len) = {
-                let mut headers: [httparse::Header; MAX_HEADERS] = unsafe { mem::uninitialized() };
+                let mut headers: [httparse::Header<'_>; MAX_HEADERS] = unsafe { mem::uninitialized() };
                 trace!("Response.parse([Header; {}], [u8; {}])", headers.len(), buf.len());
                 let mut res = httparse::Response::new(&mut headers);
                 let bytes = buf.as_ref();
@@ -666,7 +665,7 @@ impl Http1Transaction for Client {
         }
     }
 
-    fn encode(msg: Encode<Self::Outgoing>, dst: &mut Vec<u8>) -> crate::Result<Encoder> {
+    fn encode(msg: Encode<'_, Self::Outgoing>, dst: &mut Vec<u8>) -> crate::Result<Encoder> {
         trace!("Client::encode method={:?}, body={:?}", msg.head.subject.0, msg.body);
 
         *msg.req_method = Some(msg.head.subject.0.clone());
@@ -935,7 +934,7 @@ struct HeaderIndices {
 
 fn record_header_indices(
     bytes: &[u8],
-    headers: &[httparse::Header],
+    headers: &[httparse::Header<'_>],
     indices: &mut [HeaderIndices]
 ) -> Result<(), crate::error::Parse> {
     let bytes_ptr = bytes.as_ptr() as usize;
@@ -1044,7 +1043,7 @@ impl<'a> fmt::Write for FastWrite<'a> {
     }
 
     #[inline]
-    fn write_fmt(&mut self, args: fmt::Arguments) -> fmt::Result {
+    fn write_fmt(&mut self, args: fmt::Arguments<'_>) -> fmt::Result {
         fmt::write(self, args)
     }
 }
@@ -1062,7 +1061,6 @@ mod tests {
 
     #[test]
     fn test_parse_request() {
-        extern crate pretty_env_logger;
         let _ = pretty_env_logger::try_init();
         let mut raw = BytesMut::from(b"GET /echo HTTP/1.1\r\nHost: hyper.rs\r\n\r\n".to_vec());
         let mut method = None;
@@ -1082,7 +1080,6 @@ mod tests {
 
     #[test]
     fn test_parse_response() {
-        extern crate pretty_env_logger;
         let _ = pretty_env_logger::try_init();
         let mut raw = BytesMut::from(b"HTTP/1.1 200 OK\r\nContent-Length: 0\r\n\r\n".to_vec());
         let ctx = ParseContext {
diff --git a/src/proto/mod.rs b/src/proto/mod.rs
index dd33ac2141..600d39af97 100644
--- a/src/proto/mod.rs
+++ b/src/proto/mod.rs
@@ -94,7 +94,7 @@ mod body_length {
     }
 
     impl fmt::Display for DecodedLength {
-        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             match *self {
                 DecodedLength::CLOSE_DELIMITED => f.write_str("close-delimited"),
                 DecodedLength::CHUNKED => f.write_str("chunked encoding"),
diff --git a/src/server/conn.rs b/src/server/conn.rs
index baede2d7cc..2913b7c9aa 100644
--- a/src/server/conn.rs
+++ b/src/server/conn.rs
@@ -17,7 +17,6 @@ use std::sync::Arc;
 
 use bytes::Bytes;
 use futures_core::Stream;
-use h2;
 use pin_utils::{unsafe_pinned, unsafe_unpinned};
 use tokio_io::{AsyncRead, AsyncWrite};
 #[cfg(feature = "runtime")] use tokio_net::driver::Handle;
@@ -666,7 +665,7 @@ impl<I, S> fmt::Debug for Connection<I, S>
 where
     S: Service<Body>,
 {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Connection")
             .finish()
     }
diff --git a/src/server/mod.rs b/src/server/mod.rs
index 0c094307dc..e4cf6fe524 100644
--- a/src/server/mod.rs
+++ b/src/server/mod.rs
@@ -222,7 +222,7 @@ where
 }
 
 impl<I: fmt::Debug, S: fmt::Debug> fmt::Debug for Server<I, S> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Server")
             .field("listener", &self.spawn_all.incoming_ref())
             .finish()
diff --git a/src/server/tcp.rs b/src/server/tcp.rs
index 75d7d47616..7b7db2b5cf 100644
--- a/src/server/tcp.rs
+++ b/src/server/tcp.rs
@@ -182,7 +182,7 @@ fn is_connection_error(e: &io::Error) -> bool {
 }
 
 impl fmt::Debug for AddrIncoming {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("AddrIncoming")
             .field("addr", &self.addr)
             .field("sleep_on_errors", &self.sleep_on_errors)
diff --git a/src/service/make_service.rs b/src/service/make_service.rs
index 83b7521941..58a2e1ab3d 100644
--- a/src/service/make_service.rs
+++ b/src/service/make_service.rs
@@ -201,7 +201,7 @@ where
 }
 
 impl<F> fmt::Debug for MakeServiceFn<F> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("MakeServiceFn")
             .finish()
     }
diff --git a/src/service/service.rs b/src/service/service.rs
index 50bcdff370..041442e2e9 100644
--- a/src/service/service.rs
+++ b/src/service/service.rs
@@ -122,7 +122,7 @@ where
 }
 
 impl<F, R> fmt::Debug for ServiceFn<F, R> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("impl Service")
             .finish()
     }
diff --git a/src/upgrade.rs b/src/upgrade.rs
index 6dc5b4a131..618cc4e61d 100644
--- a/src/upgrade.rs
+++ b/src/upgrade.rs
@@ -160,7 +160,7 @@ impl AsyncWrite for Upgraded {
 }
 
 impl fmt::Debug for Upgraded {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Upgraded")
             .finish()
     }
@@ -198,7 +198,7 @@ impl Future for OnUpgrade {
 }
 
 impl fmt::Debug for OnUpgrade {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("OnUpgrade")
             .finish()
     }
@@ -223,7 +223,7 @@ impl Pending {
 // ===== impl UpgradeExpected =====
 
 impl fmt::Display for UpgradeExpected {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str(self.description())
     }
 }
diff --git a/tests/client.rs b/tests/client.rs
index 702c2a91ee..c88c6f8d75 100644
--- a/tests/client.rs
+++ b/tests/client.rs
@@ -1,13 +1,7 @@
 #![deny(warnings)]
-extern crate bytes;
-extern crate hyper;
+#![warn(rust_2018_idioms)]
+
 #[macro_use] extern crate matches;
-extern crate net2;
-extern crate pretty_env_logger;
-extern crate tokio;
-extern crate tokio_io;
-extern crate tokio_net;
-extern crate tokio_timer;
 
 use std::io::{Read, Write};
 use std::net::{SocketAddr, TcpListener};
@@ -777,9 +771,6 @@ mod dispatch_impl {
 
     use hyper::client::connect::{Connect, Connected, Destination, HttpConnector};
     use hyper::Client;
-    use hyper;
-
-
 
     #[test]
     fn drop_body_before_eof_closes_connection() {
@@ -1609,7 +1600,7 @@ mod dispatch_impl {
     impl AsyncRead for DebugStream {
         fn poll_read(
             mut self: Pin<&mut Self>,
-            cx: &mut Context,
+            cx: &mut Context<'_>,
             buf: &mut [u8],
         ) -> Poll<Result<usize, io::Error>> {
             Pin::new(&mut self.0).poll_read(cx, buf)
@@ -2171,7 +2162,7 @@ mod conn {
     impl AsyncRead for DebugStream {
         fn poll_read(
             mut self: Pin<&mut Self>,
-            cx: &mut Context,
+            cx: &mut Context<'_>,
             buf: &mut [u8],
         ) -> Poll<Result<usize, io::Error>> {
             Pin::new(&mut self.tcp).poll_read(cx, buf)
diff --git a/tests/server.rs b/tests/server.rs
index 4e4f29ccd7..5f37947321 100644
--- a/tests/server.rs
+++ b/tests/server.rs
@@ -1,14 +1,6 @@
 #![feature(async_closure)]
 #![deny(warnings)]
-extern crate http;
-extern crate hyper;
-extern crate h2;
-extern crate net2;
-extern crate spmc;
-extern crate pretty_env_logger;
-extern crate tokio;
-extern crate tokio_io;
-extern crate tokio_net;
+#![warn(rust_2018_idioms)]
 
 use std::net::{TcpStream, Shutdown, SocketAddr};
 use std::io::{self, Read, Write};
@@ -1241,7 +1233,7 @@ fn http_connect() {
 
 #[test]
 fn upgrades_new() {
-    use crate::tokio::io::{AsyncReadExt, AsyncWriteExt};
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
 
     let _ = pretty_env_logger::try_init();
     let mut rt = Runtime::new().unwrap();
@@ -1765,7 +1757,7 @@ impl Serve {
         Ok(buf)
     }
 
-    fn reply(&self) -> ReplyBuilder {
+    fn reply(&self) -> ReplyBuilder<'_> {
         ReplyBuilder {
             tx: &self.reply_tx
         }
diff --git a/tests/support/mod.rs b/tests/support/mod.rs
index bfdd19384a..1d5eae1aea 100644
--- a/tests/support/mod.rs
+++ b/tests/support/mod.rs
@@ -1,21 +1,17 @@
-pub extern crate hyper;
-pub extern crate tokio;
-extern crate futures_util;
-
 use std::future::Future;
 use std::pin::Pin;
 use std::sync::{Arc, Mutex, atomic::{AtomicUsize, Ordering}};
 use std::time::{Duration/*, Instant*/};
 
-use crate::hyper::{Body, Client, Request, Response, Server, Version};
-use crate::hyper::client::HttpConnector;
-use crate::hyper::service::{make_service_fn, service_fn};
+use hyper::{Body, Client, Request, Response, Server, Version};
+use hyper::client::HttpConnector;
+use hyper::service::{make_service_fn, service_fn};
 
 pub use std::net::SocketAddr;
-pub use self::futures_util::{future, try_future, FutureExt as _, StreamExt as _, TryFutureExt as _, TryStreamExt as _};
+pub use futures_util::{future, try_future, FutureExt as _, StreamExt as _, TryFutureExt as _, TryStreamExt as _};
 //pub use self::futures_channel::oneshot;
-pub use self::hyper::{HeaderMap, StatusCode};
-pub use self::tokio::runtime::current_thread::Runtime;
+pub use hyper::{HeaderMap, StatusCode};
+pub use tokio::runtime::current_thread::Runtime;
 
 macro_rules! t {
     (
@@ -209,12 +205,12 @@ macro_rules! __internal_headers_map {
 
 macro_rules! __internal_headers_eq {
     (@pat $name: expr, $pat:pat) => {
-        ::std::sync::Arc::new(move |__hdrs: &crate::hyper::HeaderMap| {
+        ::std::sync::Arc::new(move |__hdrs: &hyper::HeaderMap| {
             match __hdrs.get($name) {
                 $pat => (),
                 other => panic!("headers[{}] was not {}: {:?}", stringify!($name), stringify!($pat), other),
             }
-        }) as ::std::sync::Arc<dyn Fn(&crate::hyper::HeaderMap) + Send + Sync>
+        }) as ::std::sync::Arc<dyn Fn(&hyper::HeaderMap) + Send + Sync>
     };
     (@val $name: expr, NONE) => {
         __internal_headers_eq!(@pat $name, None);
@@ -224,13 +220,13 @@ macro_rules! __internal_headers_eq {
     };
     (@val $name: expr, $val:expr) => ({
         let __val = Option::from($val);
-        ::std::sync::Arc::new(move |__hdrs: &crate::hyper::HeaderMap| {
+        ::std::sync::Arc::new(move |__hdrs: &hyper::HeaderMap| {
             if let Some(ref val) = __val {
                 assert_eq!(__hdrs.get($name).expect(stringify!($name)), val.to_string().as_str(), stringify!($name));
             } else {
                 assert_eq!(__hdrs.get($name), None, stringify!($name));
             }
-        }) as ::std::sync::Arc<dyn Fn(&crate::hyper::HeaderMap) + Send + Sync>
+        }) as ::std::sync::Arc<dyn Fn(&hyper::HeaderMap) + Send + Sync>
     });
     ($headers:ident, { $($name:expr => $val:tt,)* }) => {
         $(
@@ -306,7 +302,6 @@ pub struct __TestConfig {
 }
 
 pub fn __run_test(cfg: __TestConfig) {
-    extern crate pretty_env_logger;
     let _ = pretty_env_logger::try_init();
     let mut rt = Runtime::new().expect("new rt");
 
@@ -379,7 +374,7 @@ pub fn __run_test(cfg: __TestConfig) {
             let fut = connecting
                 .then(|res| res.expect("connecting"))
                 .map(|conn_res| conn_res.expect("server connection error"));
-            crate::tokio::spawn(fut);
+            tokio::spawn(fut);
             future::ok::<_, hyper::Error>(cnt)
         })
         .map(|res| {