diff --git a/Cargo.toml b/Cargo.toml
index 040f179..6f21f10 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,6 +35,7 @@ socks = { version = "0.3", optional = true }
 serde = { version = "1", optional = true }
 serde_json = { version = "1", optional = true }
 encoding_rs = { version = "0.8", optional = true }
+sync_wrapper = { version = "0.1" } 
 cookie_store = { version = "0.15", optional = true, default-features = false, features = ["preserve_order"] }
 log = "0.4"
 webpki = { version = "0.22", optional = true }
diff --git a/src/response.rs b/src/response.rs
index 128b5c8..23508b8 100644
--- a/src/response.rs
+++ b/src/response.rs
@@ -3,6 +3,7 @@ use std::str::FromStr;
 use std::{fmt, io::BufRead};
 
 use chunked_transfer::Decoder as ChunkDecoder;
+use sync_wrapper::SyncWrapper;
 use url::Url;
 
 use crate::error::{Error, ErrorKind::BadStatus};
@@ -67,7 +68,7 @@ pub struct Response {
     // Boxed to avoid taking up too much size.
     unit: Option<Box<Unit>>,
     // Boxed to avoid taking up too much size.
-    stream: Box<Stream>,
+    stream: SyncWrapper<Box<Stream>>,
     /// The redirect history of this response, if any. The history starts with
     /// the first response received and ends with the response immediately
     /// previous to this one.
@@ -292,7 +293,7 @@ impl Response {
             self.length
         };
 
-        let stream = self.stream;
+        let stream = self.stream.into_inner();
         let unit = self.unit;
         if let Some(unit) = &unit {
             let result = stream.set_read_timeout(unit.agent.config.timeout_read);
@@ -512,7 +513,7 @@ impl Response {
             status,
             headers,
             unit: unit.map(Box::new),
-            stream: Box::new(stream.into()),
+            stream: SyncWrapper::new(Box::new(stream.into())),
             history: vec![],
             length,
             compression,
@@ -522,7 +523,7 @@ impl Response {
     #[cfg(test)]
     pub fn into_written_bytes(self) -> Vec<u8> {
         // Deliberately consume `self` so that any access to `self.stream` must be non-shared.
-        self.stream.written_bytes()
+        self.stream.into_inner().written_bytes()
     }
 
     #[cfg(test)]
diff --git a/src/stream.rs b/src/stream.rs
index 10e25d6..c8cee56 100644
--- a/src/stream.rs
+++ b/src/stream.rs
@@ -18,7 +18,7 @@ use crate::error::ErrorKind;
 use crate::unit::Unit;
 
 /// Trait for things implementing [std::io::Read] + [std::io::Write]. Used in [TlsConnector].
-pub trait ReadWrite: Read + Write + Send + Sync + 'static {
+pub trait ReadWrite: Read + Write + Send + 'static {
     fn socket(&self) -> Option<&TcpStream>;
 }
 
@@ -31,7 +31,7 @@ pub trait TlsConnector: Send + Sync {
 }
 
 pub(crate) struct Stream {
-    inner: BufReader<Box<dyn Inner + Send + Sync + 'static>>,
+    inner: BufReader<Box<dyn Inner + Send + 'static>>,
 }
 
 trait Inner: Read + Write {
@@ -188,7 +188,7 @@ impl fmt::Debug for Stream {
 }
 
 impl Stream {
-    fn new(t: impl Inner + Send + Sync + 'static) -> Stream {
+    fn new(t: impl Inner + Send + 'static) -> Stream {
         Stream::logged_create(Stream {
             inner: BufReader::new(Box::new(t)),
         })