diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index da54f4741..cc0807888 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -191,7 +191,7 @@ jobs:
 
     strategy:
       matrix:
-        rust: [1.39.0]
+        rust: [1.45.2]
 
     steps:
       - name: Checkout
diff --git a/Cargo.toml b/Cargo.toml
index 4efc1e15d..5bc1686b8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,7 +28,7 @@ default = ["default-tls"]
 
 # Note: this doesn't enable the 'native-tls' feature, which adds specific
 # functionality for it.
-default-tls = ["hyper-tls", "native-tls-crate", "__tls", "tokio-tls"]
+default-tls = ["hyper-tls", "native-tls-crate", "__tls", "tokio-native-tls"]
 
 # Enables native-tls specific functionality not available by default.
 native-tls = ["default-tls"]
@@ -39,13 +39,13 @@ rustls-tls-manual-roots = ["__rustls"]
 rustls-tls-webpki-roots = ["webpki-roots", "__rustls"]
 rustls-tls-native-roots = ["rustls-native-certs", "__rustls"]
 
-blocking = ["futures-util/io", "tokio/rt-threaded", "tokio/rt-core", "tokio/sync"]
+blocking = ["futures-util/io", "tokio/rt-multi-thread", "tokio/sync"]
 
 cookies = ["cookie_crate", "cookie_store", "time"]
 
-gzip = ["async-compression", "async-compression/gzip"]
+gzip = ["async-compression", "async-compression/gzip", "tokio-util"]
 
-brotli = ["async-compression", "async-compression/brotli"]
+brotli = ["async-compression", "async-compression/brotli", "tokio-util"]
 
 json = ["serde_json"]
 
@@ -71,7 +71,7 @@ __internal_proxy_sys_no_cache = []
 [dependencies]
 http = "0.2"
 url = "2.2"
-bytes = "0.5"
+bytes = "1.0"
 serde = "1.0"
 serde_urlencoded = "0.7"
 mime_guess = "2.0"
@@ -83,29 +83,29 @@ base64 = "0.13"
 encoding_rs = "0.8"
 futures-core = { version = "0.3.0", default-features = false }
 futures-util = { version = "0.3.0", default-features = false }
-http-body = "0.3.0"
-hyper = { version = "0.13.4", default-features = false, features = ["tcp"] }
+http-body = "0.4.0"
+hyper = { version = "0.14", default-features = false, features = ["tcp", "http1", "http2", "client"] }
 lazy_static = "1.4"
 log = "0.4"
 mime = "0.3.7"
 percent-encoding = "2.1"
-tokio = { version = "0.2.5", default-features = false, features = ["tcp", "time"] }
+tokio = { version = "1.0", default-features = false, features = ["net", "time"] }
 pin-project-lite = "0.2.0"
 ipnet = "2.3"
 
 # Optional deps...
 
 ## default-tls
-hyper-tls = { version = "0.4", optional = true }
+hyper-tls = { version = "0.5", optional = true }
 native-tls-crate = { version = "0.2", optional = true, package = "native-tls" }
-tokio-tls = { version = "0.3.0", optional = true }
+tokio-native-tls = { version = "0.3.0", optional = true }
 
 # rustls-tls
-hyper-rustls = { version = "0.21", default-features = false, optional = true }
-rustls = { version = "0.18", features = ["dangerous_configuration"], optional = true }
-tokio-rustls = { version = "0.14", optional = true }
-webpki-roots = { version = "0.20", optional = true }
-rustls-native-certs = { version = "0.4", optional = true }
+hyper-rustls = { version = "0.22.1", default-features = false, optional = true }
+rustls = { version = "0.19", features = ["dangerous_configuration"], optional = true }
+tokio-rustls = { version = "0.22", optional = true }
+webpki-roots = { version = "0.21", optional = true }
+rustls-native-certs = { version = "0.5", optional = true }
 
 ## cookies
 cookie_crate = { version = "0.14", package = "cookie", optional = true }
@@ -113,23 +113,23 @@ cookie_store = { version = "0.12", optional = true }
 time = { version = "0.2.11", optional = true }
 
 ## compression
-async-compression = { version = "0.3.0", default-features = false, features = ["stream"], optional = true }
-
+async-compression = { version = "0.3.7", default-features = false, features = ["tokio"], optional = true }
+tokio-util = { version = "0.6.0", default-features = false, features = ["codec", "io"], optional = true }
 
 ## socks
-tokio-socks = { version = "0.3", optional = true }
+tokio-socks = { version = "0.5", optional = true }
 
 ## trust-dns
-trust-dns-resolver = { version = "0.19", optional = true }
+trust-dns-resolver = { version = "0.20", optional = true }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
-env_logger = "0.7"
-hyper = { version = "0.13", default-features = false, features = ["tcp", "stream"] }
+env_logger = "0.8"
+hyper = { version = "0.14", default-features = false, features = ["tcp", "stream", "http1", "http2", "client", "server"] }
 serde = { version = "1.0", features = ["derive"] }
 libflate = "1.0"
 brotli_crate = { package = "brotli", version = "3.3.0" }
 doc-comment = "0.3"
-tokio = { version = "0.2.0", default-features = false, features = ["macros"] }
+tokio = { version = "1.0", default-features = false, features = ["macros", "rt-multi-thread"] }
 
 [target.'cfg(windows)'.dependencies]
 winreg = "0.7"
diff --git a/src/async_impl/body.rs b/src/async_impl/body.rs
index 762d70a6c..2c1616669 100644
--- a/src/async_impl/body.rs
+++ b/src/async_impl/body.rs
@@ -7,7 +7,7 @@ use bytes::Bytes;
 use futures_core::Stream;
 use http_body::Body as HttpBody;
 use pin_project_lite::pin_project;
-use tokio::time::Delay;
+use tokio::time::Sleep;
 
 /// An asynchronous request body.
 pub struct Body {
@@ -27,7 +27,7 @@ enum Inner {
                     + Sync,
             >,
         >,
-        timeout: Option<Delay>,
+        timeout: Option<Pin<Box<Sleep>>>,
     },
 }
 
@@ -103,7 +103,7 @@ impl Body {
         }
     }
 
-    pub(crate) fn response(body: hyper::Body, timeout: Option<Delay>) -> Body {
+    pub(crate) fn response(body: hyper::Body, timeout: Option<Pin<Box<Sleep>>>) -> Body {
         Body {
             inner: Inner::Streaming {
                 body: Box::pin(WrapHyper(body)),
@@ -217,7 +217,7 @@ impl HttpBody for ImplStream {
                 ref mut timeout,
             } => {
                 if let Some(ref mut timeout) = timeout {
-                    if let Poll::Ready(()) = Pin::new(timeout).poll(cx) {
+                    if let Poll::Ready(()) = timeout.as_mut().poll(cx) {
                         return Poll::Ready(Some(Err(crate::error::body(crate::error::TimedOut))));
                     }
                 }
diff --git a/src/async_impl/client.rs b/src/async_impl/client.rs
index 0b842f0e8..089564dee 100644
--- a/src/async_impl/client.rs
+++ b/src/async_impl/client.rs
@@ -26,7 +26,7 @@ use rustls::RootCertStore;
 use std::future::Future;
 use std::pin::Pin;
 use std::task::{Context, Poll};
-use tokio::time::Delay;
+use tokio::time::Sleep;
 use pin_project_lite::pin_project;
 
 use log::debug;
@@ -96,7 +96,6 @@ struct Config {
     #[cfg(feature = "__tls")]
     tls: TlsBackend,
     http2_only: bool,
-    http1_writev: Option<bool>,
     http1_title_case_headers: bool,
     http2_initial_stream_window_size: Option<u32>,
     http2_initial_connection_window_size: Option<u32>,
@@ -151,7 +150,6 @@ impl ClientBuilder {
                 #[cfg(feature = "__tls")]
                 tls: TlsBackend::default(),
                 http2_only: false,
-                http1_writev: None,
                 http1_title_case_headers: false,
                 http2_initial_stream_window_size: None,
                 http2_initial_connection_window_size: None,
@@ -316,10 +314,6 @@ impl ClientBuilder {
             builder.http2_only(true);
         }
 
-        if let Some(http1_writev) = config.http1_writev {
-            builder.http1_writev(http1_writev);
-        }
-
         if let Some(http2_initial_stream_window_size) = config.http2_initial_stream_window_size {
             builder.http2_initial_stream_window_size(http2_initial_stream_window_size);
         }
@@ -655,14 +649,6 @@ impl ClientBuilder {
         self
     }
 
-    /// Force hyper to use either queued(if true), or flattened(if false) write strategy
-    /// This may eliminate unnecessary cloning of buffers for some TLS backends
-    /// By default hyper will try to guess which strategy to use
-    pub fn http1_writev(mut self, writev: bool) -> ClientBuilder {
-        self.config.http1_writev = Some(writev);
-        self
-    }
-
     /// Only use HTTP/2.
     pub fn http2_prior_knowledge(mut self) -> ClientBuilder {
         self.config.http2_only = true;
@@ -1103,7 +1089,8 @@ impl Client {
 
         let timeout = timeout
             .or(self.inner.request_timeout)
-            .map(tokio::time::delay_for);
+            .map(tokio::time::sleep)
+            .map(Box::pin);
 
         *req.headers_mut() = headers.clone();
 
@@ -1317,7 +1304,7 @@ pin_project! {
         #[pin]
         in_flight: ResponseFuture,
         #[pin]
-        timeout: Option<Delay>,
+        timeout: Option<Pin<Box<Sleep>>>,
     }
 }
 
@@ -1326,7 +1313,7 @@ impl PendingRequest {
         self.project().in_flight
     }
 
-    fn timeout(self: Pin<&mut Self>) -> Pin<&mut Option<Delay>> {
+    fn timeout(self: Pin<&mut Self>) -> Pin<&mut Option<Pin<Box<Sleep>>>> {
         self.project().timeout
     }
 
diff --git a/src/async_impl/decoder.rs b/src/async_impl/decoder.rs
index e5c9c3f31..26def2050 100644
--- a/src/async_impl/decoder.rs
+++ b/src/async_impl/decoder.rs
@@ -4,10 +4,10 @@ use std::pin::Pin;
 use std::task::{Context, Poll};
 
 #[cfg(feature = "gzip")]
-use async_compression::stream::GzipDecoder;
+use async_compression::tokio::bufread::GzipDecoder;
 
 #[cfg(feature = "brotli")]
-use async_compression::stream::BrotliDecoder;
+use async_compression::tokio::bufread::BrotliDecoder;
 
 use bytes::Bytes;
 use futures_core::Stream;
@@ -15,6 +15,11 @@ use futures_util::stream::Peekable;
 use http::HeaderMap;
 use hyper::body::HttpBody;
 
+#[cfg(any(feature = "gzip", feature = "brotli"))]
+use tokio_util::io::StreamReader;
+#[cfg(any(feature = "gzip", feature = "brotli"))]
+use tokio_util::codec::{BytesCodec, FramedRead};
+
 use super::super::Body;
 use crate::error;
 
@@ -39,11 +44,11 @@ enum Inner {
 
     /// A `Gzip` decoder will uncompress the gzipped response content before returning it.
     #[cfg(feature = "gzip")]
-    Gzip(GzipDecoder<Peekable<IoStream>>),
+    Gzip(FramedRead<GzipDecoder<StreamReader<Peekable<IoStream>, Bytes>>, BytesCodec>),
 
     /// A `Brotli` decoder will uncompress the brotlied response content before returning it.
     #[cfg(feature = "brotli")]
-    Brotli(BrotliDecoder<Peekable<IoStream>>),
+    Brotli(FramedRead<BrotliDecoder<StreamReader<Peekable<IoStream>, Bytes>>, BytesCodec>),
 
     /// A decoder that doesn't have a value yet.
     #[cfg(any(feature = "brotli", feature = "gzip"))]
@@ -229,7 +234,7 @@ impl Stream for Decoder {
             #[cfg(feature = "gzip")]
             Inner::Gzip(ref mut decoder) => {
                 return match futures_core::ready!(Pin::new(decoder).poll_next(cx)) {
-                    Some(Ok(bytes)) => Poll::Ready(Some(Ok(bytes))),
+                    Some(Ok(bytes)) => Poll::Ready(Some(Ok(bytes.freeze()))),
                     Some(Err(err)) => Poll::Ready(Some(Err(crate::error::decode_io(err)))),
                     None => Poll::Ready(None),
                 };
@@ -237,7 +242,7 @@ impl Stream for Decoder {
             #[cfg(feature = "brotli")]
             Inner::Brotli(ref mut decoder) => {
                 return match futures_core::ready!(Pin::new(decoder).poll_next(cx)) {
-                    Some(Ok(bytes)) => Poll::Ready(Some(Ok(bytes))),
+                    Some(Ok(bytes)) => Poll::Ready(Some(Ok(bytes.freeze()))),
                     Some(Err(err)) => Poll::Ready(Some(Err(crate::error::decode_io(err)))),
                     None => Poll::Ready(None),
                 };
@@ -302,9 +307,9 @@ impl Future for Pending {
 
         match self.1 {
             #[cfg(feature = "brotli")]
-            DecoderType::Brotli => Poll::Ready(Ok(Inner::Brotli(BrotliDecoder::new(_body)))),
+            DecoderType::Brotli => Poll::Ready(Ok(Inner::Brotli(FramedRead::new(BrotliDecoder::new(StreamReader::new(_body)), BytesCodec::new())))),
             #[cfg(feature = "gzip")]
-            DecoderType::Gzip => Poll::Ready(Ok(Inner::Gzip(GzipDecoder::new(_body)))),
+            DecoderType::Gzip => Poll::Ready(Ok(Inner::Gzip(FramedRead::new(GzipDecoder::new(StreamReader::new(_body)), BytesCodec::new())))),
         }
     }
 }
diff --git a/src/async_impl/multipart.rs b/src/async_impl/multipart.rs
index 526c68b95..62b56f478 100644
--- a/src/async_impl/multipart.rs
+++ b/src/async_impl/multipart.rs
@@ -521,11 +521,7 @@ mod tests {
     fn form_empty() {
         let form = Form::new();
 
-        let mut rt = runtime::Builder::new()
-            .basic_scheduler()
-            .enable_all()
-            .build()
-            .expect("new rt");
+        let rt = runtime::Builder::new_current_thread().enable_all().build().expect("new rt");
         let body = form.stream().into_stream();
         let s = body.map_ok(|try_c| try_c.to_vec()).try_concat();
 
@@ -572,11 +568,7 @@ mod tests {
              --boundary\r\n\
              Content-Disposition: form-data; name=\"key3\"; filename=\"filename\"\r\n\r\n\
              value3\r\n--boundary--\r\n";
-        let mut rt = runtime::Builder::new()
-            .basic_scheduler()
-            .enable_all()
-            .build()
-            .expect("new rt");
+        let rt = runtime::Builder::new_current_thread().enable_all().build().expect("new rt");
         let body = form.stream().into_stream();
         let s = body.map(|try_c| try_c.map(|r| r.to_vec())).try_concat();
 
@@ -603,11 +595,7 @@ mod tests {
                         \r\n\
                         value2\r\n\
                         --boundary--\r\n";
-        let mut rt = runtime::Builder::new()
-            .basic_scheduler()
-            .enable_all()
-            .build()
-            .expect("new rt");
+        let rt = runtime::Builder::new_current_thread().enable_all().build().expect("new rt");
         let body = form.stream().into_stream();
         let s = body.map(|try_c| try_c.map(|r| r.to_vec())).try_concat();
 
diff --git a/src/async_impl/response.rs b/src/async_impl/response.rs
index ef7e74afd..2035f01e4 100644
--- a/src/async_impl/response.rs
+++ b/src/async_impl/response.rs
@@ -1,6 +1,7 @@
 use std::borrow::Cow;
 use std::fmt;
 use std::net::SocketAddr;
+use std::pin::Pin;
 
 use bytes::Bytes;
 use encoding_rs::{Encoding, UTF_8};
@@ -12,7 +13,7 @@ use mime::Mime;
 use serde::de::DeserializeOwned;
 #[cfg(feature = "json")]
 use serde_json;
-use tokio::time::Delay;
+use tokio::time::Sleep;
 use url::Url;
 
 use super::body::Body;
@@ -37,7 +38,7 @@ impl Response {
         res: hyper::Response<hyper::Body>,
         url: Url,
         accepts: Accepts,
-        timeout: Option<Delay>,
+        timeout: Option<Pin<Box<Sleep>>>,
     ) -> Response {
         let (parts, body) = res.into_parts();
         let status = parts.status;
diff --git a/src/blocking/body.rs b/src/blocking/body.rs
index 3cb0d1cc6..c42e418e5 100644
--- a/src/blocking/body.rs
+++ b/src/blocking/body.rs
@@ -2,10 +2,11 @@ use std::fmt;
 use std::fs::File;
 use std::future::Future;
 use std::io::{self, Cursor, Read};
-use std::mem::{self, MaybeUninit};
+use std::mem;
 use std::ptr;
 
 use bytes::Bytes;
+use bytes::buf::UninitSlice;
 
 use crate::async_impl;
 
@@ -289,14 +290,14 @@ async fn send_future(sender: Sender) -> Result<(), crate::Error> {
             if buf.remaining_mut() == 0 {
                 buf.reserve(8192);
                 // zero out the reserved memory
+                let uninit = buf.chunk_mut();
                 unsafe {
-                    let uninit = mem::transmute::<&mut [MaybeUninit<u8>], &mut [u8]>(buf.bytes_mut());
                     ptr::write_bytes(uninit.as_mut_ptr(), 0, uninit.len());
                 }
             }
 
             let bytes = unsafe {
-                mem::transmute::<&mut [MaybeUninit<u8>], &mut [u8]>(buf.bytes_mut())
+                mem::transmute::<&mut UninitSlice, &mut [u8]>(buf.chunk_mut())
             };
             match body.read(bytes) {
                 Ok(0) => {
diff --git a/src/blocking/client.rs b/src/blocking/client.rs
index 66c74dcaa..dbc16c826 100644
--- a/src/blocking/client.rs
+++ b/src/blocking/client.rs
@@ -764,7 +764,7 @@ impl ClientHandle {
             .name("reqwest-internal-sync-runtime".into())
             .spawn(move || {
                 use tokio::runtime;
-                let mut rt = match runtime::Builder::new().basic_scheduler().enable_all().build().map_err(crate::error::builder) {
+                let rt = match runtime::Builder::new_current_thread().enable_all().build().map_err(crate::error::builder) {
                     Err(e) => {
                         if let Err(e) = spawn_tx.send(Err(e)) {
                             error!("Failed to communicate runtime creation failure: {:?}", e);
diff --git a/src/blocking/wait.rs b/src/blocking/wait.rs
index cfca8da9d..801f1678d 100644
--- a/src/blocking/wait.rs
+++ b/src/blocking/wait.rs
@@ -67,10 +67,9 @@ fn enter() {
     // Check we aren't already in a runtime
     #[cfg(debug_assertions)]
     {
-        tokio::runtime::Builder::new()
-            .core_threads(1)
+        tokio::runtime::Builder::new_current_thread()
             .build()
             .expect("build shell runtime")
-            .enter(|| {});
+            .enter();
     }
 }
diff --git a/src/connect.rs b/src/connect.rs
index 3061a16ff..c58ae8407 100644
--- a/src/connect.rs
+++ b/src/connect.rs
@@ -2,22 +2,21 @@ use hyper::service::Service;
 use http::uri::{Scheme, Authority};
 use http::Uri;
 use hyper::client::connect::{Connected, Connection};
-use tokio::io::{AsyncRead, AsyncWrite};
+use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
 #[cfg(feature = "native-tls-crate")]
 use native_tls_crate::{TlsConnector, TlsConnectorBuilder};
 #[cfg(feature = "__tls")]
 use http::header::HeaderValue;
 use futures_util::future::Either;
-use bytes::{Buf, BufMut};
 
 use std::future::Future;
 use std::io;
+use std::io::IoSlice;
 use std::net::IpAddr;
 use std::pin::Pin;
 use std::sync::Arc;
 use std::task::{Context, Poll};
 use std::time::Duration;
-use std::mem::MaybeUninit;
 use pin_project_lite::pin_project;
 
 #[cfg(feature = "trust-dns")]
@@ -272,7 +271,7 @@ impl Connector {
                         .ok_or("no host in url")?
                         .to_string();
                     let conn = socks::connect(proxy, dst, dns).await?;
-                    let tls_connector = tokio_tls::TlsConnector::from(tls.clone());
+                    let tls_connector = tokio_native_tls::TlsConnector::from(tls.clone());
                     let io = tls_connector
                         .connect(&host, conn)
                         .await?;
@@ -342,13 +341,13 @@ impl Connector {
                     http.set_nodelay(true);
                 }
 
-                let tls_connector = tokio_tls::TlsConnector::from(tls.clone());
+                let tls_connector = tokio_native_tls::TlsConnector::from(tls.clone());
                 let mut http = hyper_tls::HttpsConnector::from((http, tls_connector));
                 let io = http.call(dst).await?;
 
                 if let hyper_tls::MaybeHttpsStream::Https(stream) = &io {
                     if !self.nodelay {
-                        stream.get_ref().set_nodelay(false)?;
+                        stream.get_ref().get_ref().get_ref().set_nodelay(false)?;
                     }
                 }
 
@@ -411,7 +410,7 @@ impl Connector {
                     let host = dst.host().to_owned();
                     let port = dst.port().map(|p| p.as_u16()).unwrap_or(443);
                     let http = http.clone();
-                    let tls_connector = tokio_tls::TlsConnector::from(tls.clone());
+                    let tls_connector = tokio_native_tls::TlsConnector::from(tls.clone());
                     let mut http = hyper_tls::HttpsConnector::from((http, tls_connector));
                     let conn = http.call(proxy_dst).await?;
                     log::trace!("tunneling HTTPS over proxy");
@@ -424,7 +423,7 @@ impl Connector {
                         self.user_agent.clone(),
                         auth
                     ).await?;
-                    let tls_connector = tokio_tls::TlsConnector::from(tls.clone());
+                    let tls_connector = tokio_native_tls::TlsConnector::from(tls.clone());
                     let io = tls_connector
                         .connect(&host.ok_or("no host in url")?, tunneled)
                         .await?;
@@ -569,30 +568,11 @@ impl AsyncRead for Conn {
     fn poll_read(
         self: Pin<&mut Self>,
         cx: &mut Context,
-        buf: &mut [u8]
-    ) -> Poll<io::Result<usize>> {
+        buf: &mut ReadBuf<'_>
+    ) -> Poll<io::Result<()>> {
         let this = self.project();
         AsyncRead::poll_read(this.inner, cx, buf)
     }
-
-    unsafe fn prepare_uninitialized_buffer(
-        &self,
-        buf: &mut [MaybeUninit<u8>]
-    ) -> bool {
-        self.inner.prepare_uninitialized_buffer(buf)
-    }
-
-    fn poll_read_buf<B: BufMut>(
-        self: Pin<&mut Self>,
-        cx: &mut Context,
-        buf: &mut B
-    ) -> Poll<io::Result<usize>>
-        where
-            Self: Sized
-    {
-        let this = self.project();
-        AsyncRead::poll_read_buf(this.inner, cx, buf)
-    }
 }
 
 impl AsyncWrite for Conn {
@@ -605,6 +585,19 @@ impl AsyncWrite for Conn {
         AsyncWrite::poll_write(this.inner, cx, buf)
     }
 
+    fn poll_write_vectored(
+        self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        bufs: &[IoSlice<'_>]
+    ) -> Poll<Result<usize, io::Error>> {
+        let this = self.project();
+        AsyncWrite::poll_write_vectored(this.inner, cx, bufs)
+    }
+
+    fn is_write_vectored(&self) -> bool {
+        self.inner.is_write_vectored()
+    }
+
     fn poll_flush(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<(), io::Error>> {
         let this = self.project();
         AsyncWrite::poll_flush(this.inner, cx)
@@ -617,16 +610,6 @@ impl AsyncWrite for Conn {
         let this = self.project();
         AsyncWrite::poll_shutdown(this.inner, cx)
     }
-
-    fn poll_write_buf<B: Buf>(
-        self: Pin<&mut Self>,
-        cx: &mut Context,
-        buf: &mut B
-    ) -> Poll<Result<usize, io::Error>> where
-        Self: Sized {
-        let this = self.project();
-        AsyncWrite::poll_write_buf(this.inner, cx, buf)
-    }
 }
 
 pub(crate) type Connecting =
@@ -715,13 +698,11 @@ fn tunnel_eof() -> BoxError {
 
 #[cfg(feature = "default-tls")]
 mod native_tls_conn {
-    use std::mem::MaybeUninit;
-    use std::{pin::Pin, task::{Context, Poll}};
-    use bytes::{Buf, BufMut};
+    use std::{pin::Pin, task::{Context, Poll}, io::{self, IoSlice}};
     use hyper::client::connect::{Connected, Connection};
     use pin_project_lite::pin_project;
-    use tokio::io::{AsyncRead, AsyncWrite};
-    use tokio_tls::TlsStream;
+    use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
+    use tokio_native_tls::TlsStream;
 
 
     pin_project! {
@@ -732,7 +713,7 @@ mod native_tls_conn {
 
     impl<T: Connection + AsyncRead + AsyncWrite + Unpin> Connection for NativeTlsConn<T> {
         fn connected(&self) -> Connected {
-            self.inner.get_ref().connected()
+            self.inner.get_ref().get_ref().get_ref().connected()
         }
     }
 
@@ -740,30 +721,11 @@ mod native_tls_conn {
         fn poll_read(
             self: Pin<&mut Self>,
             cx: &mut Context,
-            buf: &mut [u8]
-        ) -> Poll<tokio::io::Result<usize>> {
+            buf: &mut ReadBuf<'_>
+        ) -> Poll<tokio::io::Result<()>> {
             let this = self.project();
             AsyncRead::poll_read(this.inner, cx, buf)
         }
-
-        unsafe fn prepare_uninitialized_buffer(
-            &self,
-            buf: &mut [MaybeUninit<u8>]
-        ) -> bool {
-            self.inner.prepare_uninitialized_buffer(buf)
-        }
-
-        fn poll_read_buf<B: BufMut>(
-            self: Pin<&mut Self>,
-            cx: &mut Context,
-            buf: &mut B
-        ) -> Poll<tokio::io::Result<usize>>
-            where
-                Self: Sized
-        {
-            let this = self.project();
-            AsyncRead::poll_read_buf(this.inner, cx, buf)
-        }
     }
 
     impl<T: AsyncRead + AsyncWrite + Unpin> AsyncWrite for NativeTlsConn<T> {
@@ -776,6 +738,19 @@ mod native_tls_conn {
             AsyncWrite::poll_write(this.inner, cx, buf)
         }
 
+        fn poll_write_vectored(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            bufs: &[IoSlice<'_>]
+        ) -> Poll<Result<usize, io::Error>> {
+            let this = self.project();
+            AsyncWrite::poll_write_vectored(this.inner, cx, bufs)
+        }
+
+        fn is_write_vectored(&self) -> bool {
+            self.inner.is_write_vectored()
+        }
+
         fn poll_flush(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<(), tokio::io::Error>> {
             let this = self.project();
             AsyncWrite::poll_flush(this.inner, cx)
@@ -788,28 +763,16 @@ mod native_tls_conn {
             let this = self.project();
             AsyncWrite::poll_shutdown(this.inner, cx)
         }
-
-        fn poll_write_buf<B: Buf>(
-            self: Pin<&mut Self>,
-            cx: &mut Context,
-            buf: &mut B
-        ) -> Poll<Result<usize, tokio::io::Error>> where
-            Self: Sized {
-            let this = self.project();
-            AsyncWrite::poll_write_buf(this.inner, cx, buf)
-        }
     }
 }
 
 #[cfg(feature = "__rustls")]
 mod rustls_tls_conn {
     use rustls::Session;
-    use std::mem::MaybeUninit;
-    use std::{pin::Pin, task::{Context, Poll}};
-    use bytes::{Buf, BufMut};
+    use std::{pin::Pin, task::{Context, Poll}, io::{self, IoSlice}};
     use hyper::client::connect::{Connected, Connection};
     use pin_project_lite::pin_project;
-    use tokio::io::{AsyncRead, AsyncWrite};
+    use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
     use tokio_rustls::client::TlsStream;
 
 
@@ -833,30 +796,11 @@ mod rustls_tls_conn {
         fn poll_read(
             self: Pin<&mut Self>,
             cx: &mut Context,
-            buf: &mut [u8]
-        ) -> Poll<tokio::io::Result<usize>> {
+            buf: &mut ReadBuf<'_>
+        ) -> Poll<tokio::io::Result<()>> {
             let this = self.project();
             AsyncRead::poll_read(this.inner, cx, buf)
         }
-
-        unsafe fn prepare_uninitialized_buffer(
-            &self,
-            buf: &mut [MaybeUninit<u8>]
-        ) -> bool {
-            self.inner.prepare_uninitialized_buffer(buf)
-        }
-
-        fn poll_read_buf<B: BufMut>(
-            self: Pin<&mut Self>,
-            cx: &mut Context,
-            buf: &mut B
-        ) -> Poll<tokio::io::Result<usize>>
-            where
-                Self: Sized
-        {
-            let this = self.project();
-            AsyncRead::poll_read_buf(this.inner, cx, buf)
-        }
     }
 
     impl<T: AsyncRead + AsyncWrite + Unpin> AsyncWrite for RustlsTlsConn<T> {
@@ -869,6 +813,19 @@ mod rustls_tls_conn {
             AsyncWrite::poll_write(this.inner, cx, buf)
         }
 
+        fn poll_write_vectored(
+            self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            bufs: &[IoSlice<'_>]
+        ) -> Poll<Result<usize, io::Error>> {
+            let this = self.project();
+            AsyncWrite::poll_write_vectored(this.inner, cx, bufs)
+        }
+
+        fn is_write_vectored(&self) -> bool {
+            self.inner.is_write_vectored()
+        }
+
         fn poll_flush(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<(), tokio::io::Error>> {
             let this = self.project();
             AsyncWrite::poll_flush(this.inner, cx)
@@ -881,16 +838,6 @@ mod rustls_tls_conn {
             let this = self.project();
             AsyncWrite::poll_shutdown(this.inner, cx)
         }
-
-        fn poll_write_buf<B: Buf>(
-            self: Pin<&mut Self>,
-            cx: &mut Context,
-            buf: &mut B
-        ) -> Poll<Result<usize, tokio::io::Error>> where
-            Self: Sized {
-            let this = self.project();
-            AsyncWrite::poll_write_buf(this.inner, cx, buf)
-        }
     }
 }
 
@@ -961,10 +908,11 @@ mod socks {
 
 mod verbose {
     use std::fmt;
+    use std::io::{self, IoSlice};
     use std::pin::Pin;
     use std::task::{Context, Poll};
     use hyper::client::connect::{Connected, Connection};
-    use tokio::io::{AsyncRead, AsyncWrite};
+    use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
 
     pub(super) const OFF: Wrapper = Wrapper(false);
 
@@ -1000,12 +948,12 @@ mod verbose {
         fn poll_read(
             mut self: Pin<&mut Self>,
             cx: &mut Context,
-            buf: &mut [u8]
-        ) -> Poll<std::io::Result<usize>> {
+            buf: &mut ReadBuf<'_>
+        ) -> Poll<std::io::Result<()>> {
             match Pin::new(&mut self.inner).poll_read(cx, buf) {
-                Poll::Ready(Ok(n)) => {
-                    log::trace!("{:08x} read: {:?}", self.id, Escape(&buf[..n]));
-                    Poll::Ready(Ok(n))
+                Poll::Ready(Ok(())) => {
+                    log::trace!("{:08x} read: {:?}", self.id, Escape(buf.filled()));
+                    Poll::Ready(Ok(()))
                 },
                 Poll::Ready(Err(e)) => {
                     Poll::Ready(Err(e))
@@ -1033,6 +981,18 @@ mod verbose {
             }
         }
 
+        fn poll_write_vectored(
+            mut self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            bufs: &[IoSlice<'_>]
+        ) -> Poll<Result<usize, io::Error>> {
+            Pin::new(&mut self.inner).poll_write_vectored(cx, bufs)
+        }
+
+        fn is_write_vectored(&self) -> bool {
+            self.inner.is_write_vectored()
+        }
+
         fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Result<(), std::io::Error>> {
             Pin::new(&mut self.inner).poll_flush(cx)
         }
@@ -1137,7 +1097,7 @@ mod tests {
     fn test_tunnel() {
         let addr = mock_tunnel!();
 
-        let mut rt = runtime::Builder::new().basic_scheduler().enable_all().build().expect("new rt");
+        let rt = runtime::Builder::new_current_thread().enable_all().build().expect("new rt");
         let f = async move {
             let tcp = TcpStream::connect(&addr).await?;
             let host = addr.ip().to_string();
@@ -1152,7 +1112,7 @@ mod tests {
     fn test_tunnel_eof() {
         let addr = mock_tunnel!(b"HTTP/1.1 200 OK");
 
-        let mut rt = runtime::Builder::new().basic_scheduler().enable_all().build().expect("new rt");
+        let rt = runtime::Builder::new_current_thread().enable_all().build().expect("new rt");
         let f = async move {
             let tcp = TcpStream::connect(&addr).await?;
             let host = addr.ip().to_string();
@@ -1167,7 +1127,7 @@ mod tests {
     fn test_tunnel_non_http_response() {
         let addr = mock_tunnel!(b"foo bar baz hallo");
 
-        let mut rt = runtime::Builder::new().basic_scheduler().enable_all().build().expect("new rt");
+        let rt = runtime::Builder::new_current_thread().enable_all().build().expect("new rt");
         let f = async move {
             let tcp = TcpStream::connect(&addr).await?;
             let host = addr.ip().to_string();
@@ -1188,7 +1148,7 @@ mod tests {
         "
         );
 
-        let mut rt = runtime::Builder::new().basic_scheduler().enable_all().build().expect("new rt");
+        let rt = runtime::Builder::new_current_thread().enable_all().build().expect("new rt");
         let f = async move {
             let tcp = TcpStream::connect(&addr).await?;
             let host = addr.ip().to_string();
@@ -1207,7 +1167,7 @@ mod tests {
             "Proxy-Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==\r\n"
         );
 
-        let mut rt = runtime::Builder::new().basic_scheduler().enable_all().build().expect("new rt");
+        let rt = runtime::Builder::new_current_thread().enable_all().build().expect("new rt");
         let f = async move {
             let tcp = TcpStream::connect(&addr).await?;
             let host = addr.ip().to_string();
diff --git a/src/dns.rs b/src/dns.rs
index e533da115..adba67e65 100644
--- a/src/dns.rs
+++ b/src/dns.rs
@@ -3,6 +3,7 @@ use std::pin::Pin;
 use std::sync::Arc;
 use std::task::{self, Poll};
 use std::io;
+use std::net::SocketAddr;
 
 use hyper::client::connect::dns as hyper_dns;
 use hyper::service::Service;
@@ -10,7 +11,7 @@ use tokio::sync::Mutex;
 use trust_dns_resolver::{
     config::{ResolverConfig, ResolverOpts},
     lookup_ip::LookupIpIntoIter,
-    system_conf, AsyncResolver, TokioConnection, TokioConnectionProvider,
+    system_conf, AsyncResolver, TokioConnection, TokioConnectionProvider, TokioHandle
 };
 
 use crate::error::BoxError;
@@ -26,6 +27,10 @@ pub(crate) struct TrustDnsResolver {
     state: Arc<Mutex<State>>,
 }
 
+pub(crate) struct SocketAddrs {
+    iter: LookupIpIntoIter,
+}
+
 enum State {
     Init,
     Ready(SharedResolver),
@@ -47,7 +52,7 @@ impl TrustDnsResolver {
 }
 
 impl Service<hyper_dns::Name> for TrustDnsResolver {
-    type Response = LookupIpIntoIter;
+    type Response = SocketAddrs;
     type Error = BoxError;
     type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
 
@@ -62,7 +67,7 @@ impl Service<hyper_dns::Name> for TrustDnsResolver {
 
             let resolver = match &*lock {
                 State::Init => {
-                    let resolver = new_resolver(tokio::runtime::Handle::current()).await?;
+                    let resolver = new_resolver().await?;
                     *lock = State::Ready(resolver.clone());
                     resolver
                 },
@@ -74,18 +79,24 @@ impl Service<hyper_dns::Name> for TrustDnsResolver {
             drop(lock);
 
             let lookup = resolver.lookup_ip(name.as_str()).await?;
-            Ok(lookup.into_iter())
+            Ok(SocketAddrs { iter: lookup.into_iter() })
         })
     }
 }
 
-/// Takes a `Handle` argument as an indicator that it must be called from
-/// within the context of a Tokio runtime.
-async fn new_resolver(handle: tokio::runtime::Handle) -> Result<SharedResolver, BoxError> {
+impl Iterator for SocketAddrs {
+    type Item = SocketAddr;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.iter.next().map(|ip_addr| SocketAddr::new(ip_addr, 0))
+    }
+}
+
+async fn new_resolver() -> Result<SharedResolver, BoxError> {
     let (config, opts) = SYSTEM_CONF
         .as_ref()
         .expect("can't construct TrustDnsResolver if SYSTEM_CONF is error")
         .clone();
-    let resolver = AsyncResolver::new(config, opts, handle).await?;
+    let resolver = AsyncResolver::new(config, opts, TokioHandle)?;
     Ok(Arc::new(resolver))
 }
diff --git a/tests/blocking.rs b/tests/blocking.rs
index c98a2c319..93f204ac8 100644
--- a/tests/blocking.rs
+++ b/tests/blocking.rs
@@ -282,7 +282,9 @@ fn test_blocking_inside_a_runtime() {
 
     let url = format!("http://{}/text", server.addr());
 
-    let mut rt = tokio::runtime::Builder::new().build().expect("new rt");
+    let rt = tokio::runtime::Builder::new_current_thread()
+        .build()
+        .expect("new rt");
 
     rt.block_on(async move {
         let _should_panic = reqwest::blocking::get(&url);
diff --git a/tests/redirect.rs b/tests/redirect.rs
index c1621ca54..16f7712f5 100644
--- a/tests/redirect.rs
+++ b/tests/redirect.rs
@@ -155,14 +155,15 @@ fn test_redirect_307_does_not_try_if_reader_cannot_reset() {
 async fn test_redirect_removes_sensitive_headers() {
     use tokio::sync::watch;
 
-    let (tx, rx) = watch::channel(None);
+    let (tx, rx) = watch::channel::<Option<std::net::SocketAddr>>(None);
 
     let end_server = server::http(move |req| {
         let mut rx = rx.clone();
         async move {
             assert_eq!(req.headers().get("cookie"), None);
 
-            let mid_addr = rx.recv().await.unwrap().unwrap();
+            rx.changed().await.unwrap();
+            let mid_addr = rx.borrow().unwrap();
             assert_eq!(
                 req.headers()["referer"],
                 format!("http://{}/sensitive", mid_addr)
@@ -182,7 +183,7 @@ async fn test_redirect_removes_sensitive_headers() {
             .unwrap()
     });
 
-    tx.broadcast(Some(mid_server.addr())).unwrap();
+    tx.send(Some(mid_server.addr())).unwrap();
 
     reqwest::Client::builder()
         .build()
diff --git a/tests/support/server.rs b/tests/support/server.rs
index e64590494..4ac1a4a77 100644
--- a/tests/support/server.rs
+++ b/tests/support/server.rs
@@ -44,8 +44,7 @@ where
 {
     //Spawn new runtime in thread to prevent reactor execution context conflict
     thread::spawn(move || {
-        let mut rt = runtime::Builder::new()
-            .basic_scheduler()
+        let rt = runtime::Builder::new_current_thread()
             .enable_all()
             .build()
             .expect("new rt");
diff --git a/tests/timeouts.rs b/tests/timeouts.rs
index 25c992471..35b105e93 100644
--- a/tests/timeouts.rs
+++ b/tests/timeouts.rs
@@ -11,7 +11,7 @@ async fn client_timeout() {
     let server = server::http(move |_req| {
         async {
             // delay returning the response
-            tokio::time::delay_for(Duration::from_secs(2)).await;
+            tokio::time::sleep(Duration::from_secs(2)).await;
             http::Response::default()
         }
     });
@@ -38,7 +38,7 @@ async fn request_timeout() {
     let server = server::http(move |_req| {
         async {
             // delay returning the response
-            tokio::time::delay_for(Duration::from_secs(2)).await;
+            tokio::time::sleep(Duration::from_secs(2)).await;
             http::Response::default()
         }
     });
@@ -94,7 +94,7 @@ async fn response_timeout() {
         async {
             // immediate response, but delayed body
             let body = hyper::Body::wrap_stream(futures_util::stream::once(async {
-                tokio::time::delay_for(Duration::from_secs(2)).await;
+                tokio::time::sleep(Duration::from_secs(2)).await;
                 Ok::<_, std::convert::Infallible>("Hello")
             }));
 
@@ -134,7 +134,7 @@ fn timeout_closes_connection() {
     let server = server::http(move |_req| {
         async {
             // delay returning the response
-            tokio::time::delay_for(Duration::from_secs(2)).await;
+            tokio::time::sleep(Duration::from_secs(2)).await;
             http::Response::default()
         }
     });
@@ -158,7 +158,7 @@ fn timeout_blocking_request() {
     let server = server::http(move |_req| {
         async {
             // delay returning the response
-            tokio::time::delay_for(Duration::from_secs(2)).await;
+            tokio::time::sleep(Duration::from_secs(2)).await;
             http::Response::default()
         }
     });
@@ -191,7 +191,7 @@ fn write_timeout_large_body() {
     let server = server::http(move |_req| {
         async {
             // delay returning the response
-            tokio::time::delay_for(Duration::from_secs(2)).await;
+            tokio::time::sleep(Duration::from_secs(2)).await;
             http::Response::default()
         }
     });